*-^ 




Class j:tM^ 
Book >~R^^- 



Coipght]^" 



COPYRIGHT DEPOSIT. 



vft*: 



r 



p' 



MECHANICAL DRAWING 

SELF-TAUGHT; 

COMPRISING 

INSTRUCTIONS IN:rTHE SELECTION AND PREPARA- 
TION OF DRAWING INSTRUMENTS. 

ELEMENTARY INSTRUCTION IN 

PRACTICAL MECHANICAL DRAWING. 

TOGETHER WITH 

EXAMPLES IN SIMPLE GEOMETEY AND ELEMENTARY MECH 

ANISM, INCLUDING- SCREW THREADS, GEAR WHEELS, 

MECHANICAL MOTIONS, BNGJNES AND BOILERS. 

»■■■ 

BY JOSHUA EOSE, M..E.. 

AUTHOR OF "steam BOILERS," "MODERN STEAM ENGINES," "THE COMPLETE PRACTICAL 
MACHINIST," "PATTERN MAKER'S ASSISTANT," "THE SLIDE VALVE." 



ILL USTEATED BY THREE HUNDRED AND THIRTY ENGRA VINGS. 



FOURTH EDITION, THOROUGHLY REVISED AND CORRECTED. 
/t 



> -y^ 



PHILADELPHIA: 
HENRY CAREY BAIRD & CO., nrr a-^iRoq 

INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS, '^^^ ' ' "^ '0 0^ 



810 Walnut Street. 

LONDON : 
SAMPSON LOW, MARSTON, SEARLE & RIVINGTON, Limited 

ST. DUNSTAN'S HOUSE, FETTER LANE, FLEET STREET. 
1889. 




4' 



Copyright by JosHUA Rose, 1883. 
Copyright by Joshua Rose, 1889. 



PUILADELPHIA. 

COLLINS. PRINTKR 



PREFACE TO THE FOURTH EDITION 



TN the pages of this book, the author has sought to impart 

to the beginner, such elementary information as would 

enable him, with application and practice, to make simple 

mechanical drawings without the assistance of a teacher. 

To accomplish this end, it has been necessary to mainly 

confine the subject-matter to the actual drawing of elementary 

pieces of machinery, and in many cases to show the pencil 

lines of the drawing, which possesses great advantages for the 

learner, since it is the producing of the pencil lines that really 

proves the study, the inking-in being merely a curtailed 

repetition of the pencilling. Similarly when the drawing of 

a piece, such, for example, as a fully developed screw thread, 

is shown fully developed from end to end, even though the 

pencil lines are all shown, yet the process of construction will 

be less clear than if the process of development be shown 

gradually along the drawing. Thus beginning at an end of 

the example, the first pencil lines only may be shown, and as 

the pencilling progresses to the right-hand, the development 

may progress so that at the other, or left-hand end, the 

finished inked-in and shaded thread may be shown, and 

between these two ends will be found a part showing each 

stage of development of the thread, all the lines being num- 

(iii) 



iv PREFACE. 

bered in the order in which they were marked. This prevents 
a confusion of lines, and makes it more easy to follow or to 
copy the drawing. 

The numerous inquiries from working machinists for a 
book of this kind have led the author to its production, 
which he hopes and believes will meet the want thus indicated, 
giving to the learner a sufficiently practical knowledge of 
mechanical drawing to enable him to proceed further by 
copying such drawings as he may be able to obtain, or by the 
aid of some of the more expensive and elaborate books already 
published on the subject. 

He believes that in learning mechanical drawing without 
the aid of an instructor the chief difficulty is overcome when 
the learner has become sufficiently familiar with the instru- 
ments to be enabled to use them without hesitation or diffi- 
culty, and it is to attain this end that the chapter on plotting 
mechanical motions and the succeeding examples have been 
introduced ; these forming studies that are easily followed by 
J:he beginner, while sufficiently interesting to afford to the 
student pleasure as well as profit. 

July 15, 1889. 



CONTENTS 



CHAPTER I. 

THE DRAWING BOARD. 

The T square r8 

The triangles 19 

Curves 21 

Selecting and testing drawing instruments 22 

Lead pencils 23 

Mixing India ink 25 

The drawing paper 26 

Tracing paper ' 29 

The ink 30 

Testing and selecting India ink , 30 

Draftsmen's measuring rules 33 

CHAPTER n. 

THE PREPARATION AND USE OF THE INSTRUMENTS. 

Preparing the lining pen for use 34 

The shapes of the lining pen points 35 

Oilstoning pen points 36 

Preparing the circle pen for use ^8 

The shape for circle pen points 38 

Shaping circle pens for very small circles 39 

A form of pen point recently introduced; forming the pen point , . ... 39 

The method of oilstoning circle pen points 40 

(v) 



yl CONTENTS. 

The needle point and pen point 42 

How to use the circle pen 43 

German instrument to avoid slipping of a needle point 44 

How to use the lining pen 45 

Applying the ink to the bow-pen 46 

Using a straight line or lining pen with a T square 47 

CHAPTER III. 

LINES AND CURVES. 

Explanation of simple geometrical terms; radius; explanation of conven- 
tional dotted lines 48 

il line at a right angle to another; a point; parallel lines 49 

A line produced ; a line bisected ; a line bounding a circle ; an arc of a 
circle ; segments of a circle ; the chord of an arc ; a quadrant of a 

circle 50 

A sector of a circle ; a line tangent to a circle ; a semi-circle ; centre of a 
circle ; axis of a cylinder ; to draw a circle that shall pass through three 

given points 51 

To find the centre from which an arc of a circle has been struck ; the 

degrees of a circle 52 

The protractor 53 

To find the angle of one line to another. 5^ 

To find the angles of three lines one to the other 55 

Acute angles and obtuse angles 57 

Triangles ; right angle triangle ; obtuse angle triangle ; equilateral triangle ; 

isosceles triangle 58 

Scalene triangle ; a quadrangle ; quadrilateral or tetragon 59 

Rhomboid ; trapezoid ; trapezium 60 

The construction of polygons 61 

The names of regular polygons 62 

The angles of regular polygons ; the ellipse 63 

Form of a true ellipse 69 

The use of a trammel for drawing an ellipse 72 

To draw a parabola mechanically 73 

Tf) draw a parabola by lines 74 

To draw a cam 75 



CONTENTS. vii 

CHAPTER IV. 
SHADOW LINES AND LINE-SHADING. 

Section lining or cross-hatching 77 

To represent cylindrical pieces one within the other ; to represent a number 

of pieces one within the other 78 

To represent pieces put together and having slots or keyways through them. 79 

Effects of shading or cross-hatching So 

Lines in sectional shading or cross-hatching made to denote the material of 

which the piece is composed — lead, wood, steel, brass, wrought iron, 

cast iron 81 

Line-shading 82 

The shade line to indicate the shape of piece ; representation of a washer. . .. 83 
A key drawn with a shade line; shade line applied to a nut; a German 

pen regulated to draw lines of various breadths 84 

Example of line-shading piston, piston-rod, guide-bar, etc 85 

A cylindrical pin line-shaded ; two cylindrical pieces that join each other; a 

lathe centre ; a piece having a curved outline 86 

Line-shading applied to a ball or sphere ; applied to a pin in a socket shown 

in section Z"] 

A piece of tube, where the thickness of the tube is shown ; where the 

hollow, or hole is seen, the piece shown in section ; where the body is 

bell-mouthed and the hollow curve shown by shading 88 

Example of line-shading to denote the relative distances of various surfaces 

from the eye 89 

Line-shading to denote that the piece represented is of wood ; shade-lines 

being regular or irregular 90 

CHAPTER V. 

MARKING DIMENSIONS. 

'^i^xamples in marking dimensions , 91 

CHAPTER VI. 

THE ARRANGEMENT OF DIFFERENT VIEWS. 
The different views of a mechanical drawing; elevation; plan; general 

view ; a figure to repr^ent a solid cylinder 94 



ylll CONTENTS. 

To represent the different sides of a cube; the use of a cross to denote a 

square ^^ 

A triangular piece requires two or three views q5 

To represent a ring having hexagon cross section ; examples ; a rectangular 

piece in two views gg 

The position of the piece when in its place determines the name of the view 

in the drawing 103 

View of a lever 105 

Best method of projecting one view from another; the two systems of differ- 
ent views of a piece 106 

CHAPTER VII. 

EXAMPLES IN BOLTS, NUTS AND POLYGONS. 

To represent the thread of a small screw II2 

A bolt with a hexagon head 113 

United States standard sizes for forged or unfinished bolts and nuts 116 

The basis of the Franklin Institute or United States standard for bolts and 

nuts ; hexagonal or hexagon heads of bolts 118 

Comparison of hexagon and square heads of bolts ; chamfers 120 

"Without chamfer; best plan for view of both square and hexagon heads ... 123 

Drawing different views of hexagon heads 125 

To draw a square-headed bolt; to draw the end view of a hexagon head. . i:^ 

Use of the triangle to divide circles 129 

Scales giving the length of the sides of polygons 135 

To find what a square body which mea^res one inch on each side meas- 
ures across the corners ; to find what diameter a cylindrical piece of 
wood must be turned to which is to be squared, and each side of which 

square must measure an inch 1 36 

To find a radius across corners of a hexagon or a six-sided figure, the length 

of a side being an inch 13S 

To draw a stud ; 147 

To pencil in a cap nut ; pencilling for a link having the hubs on one side 

only 145 

Link with hubs on both sides ; pencil lines for a double eye or a knuckle 

joint 14^ 

Double eye or knuckle joint with an offset ; a connecting rod end 147 



CONTENTS. ix 

A rod end with a round stem 148 

A bolt with a square under the head 149 

Example in which the corner where the round stem meets the square 
under the head is sharp; a centre punch giving an example in 
which the flat sides gradually run out upon a circle, the edges forming 
curves 150 

CHAPTER VIII. 

SCREW THREADS AND SPIRALS. 

Screw threads for small bolts with the angles of the thread drawn in, and 

the method of doing this 152 

A double thread ; a round top and bottom thread such as the Whitworth 

thread; a left hand thread; to draw screw threads of a large diameter. 156 

Drawing the curves for screw threads 157 

To draw the United States standard thread 160 

To draw a square thread 162 

Form of template for drawing the curves of threads 165^ 

To show the thread depth in a top or end view of a nut ; to draw a spiral 

spring 366 

To obtain an accurate division of the lines that divide the pitch 167 

CHAPTER IX. 

EXAMPLES FOR PRACTICE. 

A locomotive spring; a stuffing box and gland; working drawings of a 
coupling rod ; dimensions and directions marked ; a connecting rod 
drawn and put together as it would be for the lathe, vise, or erecting 

shop 169 

Drawings for the blacksmith 172 

A locomotive frame 1 74 

Reducing scales ^ 175 

Making a drawing to scale 177 

CHAPTER X. 

PROJECTIONS. 
A spiral wound around a cylinder whose end is cut off at an angle 178 



^ CONTENTS. 

A cylindrical body joining another at a right-angle; a Tee for example.. .. iSo 

Other examples of Tees iSi 

Example of a cylinder intersecting a cone i86 

A cylindrical body whose top face if viewed from one point would appear as 

a straight line, or from another a circle i88 

CHAPTER XL 
DRAWING GEAR WHEELS. 

Names of the curves and lines of gear teeth 193 

How to draw spur wheel teeth 194 

Professor Willis' scale of tooth proportions 195 

The application of the scale 197 

How to find the curve for the tooth face 198 

To trace hypocycloides for the flanks of teeth 200 

Sectional view of a section of a wheel for showing the dimensions through 

the arms and hub 202 

To draw an edge view of a wheel ; rules for drawing the teeth of wheels ; 

bevel gear wheels 203 

The construction to find the curves 204 

To draw the arcs for the teeth 205 

To draw the pitch circle of the inner and small end of the pinion teeth .... 206 

One-half of a bevel gear and an edge view projected from the same 207 

A pair of bevel wheels shown in section ; drawing of a part of an Ames 

lathe feed motion ; small bevel gears 208 

Example in which part of the gear is shown with teeth in, and the remain- 
der illustrated by circles ; drawings of part of the feed motion of a 

Niles horizontal tool work boring mill 209 

Examples in drawing elliptical gearing 210 

Various examples of laying out gear wheels. 214 

CHAPTER XIL 

PLOTTING MECHANICAL MOTIONS. 
To fmd how much motion an eccentric will give to its rod 223 



CONTENTS. Xi 

To find how much a given amount of motion of a long arm will move the 

short arm of a lever 224 

Example of the end of a lever acting directly on a shoe ; a short arm having 

a roller acting upon a larger roller 225 

A link introduced in the place of the roller to find the amount of motion of 
the rod ; a lever actuathig a plunger in a vertical line, to find how much 
a given amount of motion of the long arm will actuate the plunger .... 226 
Two levers upon their axles or shafts, the arms connected by a link and one 

arm connected to a rod 227 

A lever arm and cam in one piece on a shaft, a shoe sliding on the line, 
and held against the cam face by the rod, to find the position of the 

face of the shoe against the cam 228 

To find the amount of motion imparted in a straight line to a rod, attached 

to an eccentric strap 229 

Examples in drawing the cut-off cams employed instead of eccentrics on 
river steamboats in the Western and Southern States. Different views 

of a pair of cams 232 

The object of using a cam instead of an eccentric 234 

Method of drawing or marking out a full stroke cam 237 

Illustration of the lines embracing cut-off cams of varying limits of cut-off... 240 
Part played by. the stroke of the engine in determining the conformation 
of cut-off cams ; manner of finding essential points of drawings of cut- 
off cams 241 

A cam designed to cut off the steam at five-eighths of the piston stroke 244 

Three-fourths and seven-eighths cams 246 

Necessary imperfections in the operations of cut-off cams 247 

Drawing representing the motion which a crank imparts to a connecting rod. 249 

Plotting out the motion of a shaper link quick return 250 

Plotting out the Whitworth quick return motion employed in machines 253 

Finding the curves for moulding cutters 257 

CHAPTER XIII. 

MECHANICAL DRAWINGS FROM WHICH ENGRAVINGS ARE 
TO BE MADE. 

Making drawings for engraving , 264 

Drawings for photc-engraving 265 



xii CONTENTS. 

Drawings for engravers on wood 266 

Drawings for the wax process 267 

CHAPTER XIV. 

EXAMPLES FOR PRACTICE. 

Examples for practice 268 

Examples of drawings half in elevation and half in section 269 

Examples in globe valves 270 

The lift of globe valves 274 

Examples in drawings of band sawing machines 275 

Examples in drawings for lathes 279 

CHAPTER XV. 

EXAMPLES OF ENGINE WORK. 
Drawings of an automatic high speed engine ; side and end view of the 

engine; vertical section of the cylinder through the valve face 281 

Valve motion ; governor 284 

Pillow box, block crank-pin, wheel and main journal 286 

Side and edge view of the connecting rod 287 

A two hundred horse power horizontal steam boiler for a stationary engine ; 

cross sectional view of the boiler shell 288 

Side elevation, end view of the boiler, and setting 289 

Front elevation of boiler 290 

Working drawings of a one hundred horse power engine ; plan and side 
view of the bed plate, with the main bearing and guide bars ; cross 
sections of the bed plate ; side elevation of the cylinder, with end view 

of the same 291 

Steam chest side and horizontal cross section of the cylinder ; steam chest 
and the valves; cam wrist plate and cut-off mechanism; shaft for the 
cam plate ; cross head ; side view and section through the centre of 

the eccentric and strap 293 

Construction of the connecting rod 294 

Index 295 



Mechanical Drawing 



ELIF-T^TJa-KIT. 



CHAPTER I. 

THE DRAWING BOARD. 

A Drawing Board should be of soft pine and free 
from knots, so that it will easily receive the pins or tacks 
used to fasten down the paper. Its surface should be 
flat and level, or a little rounding, so that the paper 
shall lie close to its surface, which is one of the first 




requisites in making a good drawing. Its edges 
should be straight and at a right angle one to the 
other, and the ends of the battens B B in Figure i 

2 (17) 



1 3 MECHAXICAL DRAWING SELF-TAUGHT. 

should fall a little short of the edge A of the board, so 
that if the latter shrinks they will not protrude. The 
size of the board of course depends upon the size of 
the paper, hence it is best to obtain a board as small 
as will answer for the size of paper it is intended to 
use. The student will find it most convenient as well 
as cheapest to learn on small drawings rather than 
large ones, since they take less time to make, and cost 
less for paper; and although they require more skill to 
make, yet are preferable for the beginner, because 
he does not require to reach so far over the board, and 
furthermore, they teach him more quickly and effec- 
tively. He who can make a fair drawing having 
short lines and small curves can make a better one 
if it has large curves, etc., because it is easier to draw 
a large than a very small circle or curve. It is un- 
necessary to enter into a description of the various 
kinds of drawing boards in use, because if the student 
purchases one he will be duly informed of the kinds 
and their special features, while if he intends to make 
one the sketch in Figure i will give him all the infor- 
mation he requires, save that, as before noted, the 
wood must be soft pine, well seasoned and free from 
knots, while the battens B should be dovetailed in and 
the face of the board trued after they are glued and 
driven in. To true the edges square, it is best to 
make the two longest edges parallel and straight, and 
then the ends may be squared from those long edges. 

THE T SQUARE. 

Drawing squares or T squares, as they are termed, 
are made of wood, of hard rubber and of steel. 



THE DRAWING BOARD. 



19 



There are several kinds of T squares ; in one the 
blade is solid, as it is shown in Figure 5 on page 20 ; in 
another the back of the square is pivoted, so that the 
blade can be set to draw lines at an angle as well as 
across the board, which is often very convenient, 
although this double back prevents the triangles, when 
used in some positions, from coming close enough to 
the left hand side of the board. In an improved 
form of steel square, with pivoted blade, shown in 
Figure 2, the back is provided with a half circle divided 




Fig. 2. 

into the degrees of a circle, so that the blade can be 
set to any required degree of angle at once. 





THE TRIANGLES. 

Two triangles are all that are absolutely necessary 
for a beginner. The first is that shown in Figure 3, 



20 MECHANICAL DRAWING SELF-TAUGHT. 

which is called a triangle of 45 degrees, because its 
edge A is at that angle to edges B and C. That in 
Fioure 4 is called a trianorle of 60 deo^rees, its ed^-e A 
being at 60 degrees to B, and at 30 degrees to C. The 
edges P and C are at a right angle or an angle of 90 
degrees in both figures ; hence they are in this respect 
alike. By means of these triangles alone, a great 
many straight line drawings may be made with ease 
without the use of a drawing square ; but it is better 
for the beginner to use the square at first. The man- 
ner of using these triangles with the square is shown 




Fig- 5- 

in Figure 5, in which the triangle, Figure 3, is shown in 
three positions marked D E F, and that shown in Fig- 
ure 4 is shown in three positions, marked respectively 
G H and I. It is obvious, however, that by turning 
I over, end for end, another position is attained. The 
usefulness in these particular triangles is because in 
the various positions shown they are capable of use 
for drawing a very large proportion of the lines that 
occur in mechanical drawing. The principal require- 
ment in their use is to hold them firmly to the square- 



THE DRAWING BOARD. 



21 



blade without moving it, and without permitting them 
to move upon it. The learner will find that this is 
best attained by so regulating the height of the 
square-blade that the line to be drawn does not come 
down too near the bottom of the triangle or edge of 
the square-blade, nor too high on the triangle ; that is 
to say, too near its uppermost point. It is the left- 
hand edee of the triangle that is used, whenever it can 
be done, to produce the required line. 




CURVES. 

To draw curves that are not formed of arcs or parts 
of circles, templates called curves are provided, exam- 
ples of these forms being given in Figure 6. They 
are made in wood and in hard rubber, the latter being 
most durable ; their uses are so obvious as to require 
no explanation. It may be remar]:ed, however, that 
the use of curves gives excellent practice, because 
they must be adjusted very accurately to produce 
good results, and the dravv^ing pen must be held in the 



22 MECHAXICAL DRAWING SELF-TAUGHT. 

same vertical plane, or the curve drawn will not be 
true in its outline. 

DRAWING INSTRUMENTS. 

It is not intended or necessary to enter into an 
elaborate discussion of the various kinds of drawincr 
instruments, since the purchaser can obtain a good 
set of drawmg instruments from a reputable dealer by 
paying a proportionate price, and must per force learn 
to use such as his means enable him to purchase. 
It is recommended that the beginner purchase as 
good a set of instruments as his means will permit, 
and that if his means are limited he purchase less 
than a full set of instruments, having the same of good 
quality. 

All the instruments that need be used in the exam- 
ples of this book are as follows: 

A small spring bow-pen for circles, a lining pen or 
pen for straight lines, a small spring bow-pencil for 
circles, a large bow-pen with a removable leg to re- 
place by a divider leg or a pencil leg, and having an 
extension piece to increase its capacity. 

The spring bow-pen should have a stiff spring, and 
should be opened out to its full capacity to see that 
the spring acts well when so opened out, keeping the 
legs stiff when opened for the larger diameters. The 
purchaser should see that the joint for opening and 
closing the legs is an easy but not a loose fit on the 
screw, and that the legs will not move sideways. To 
test this latter, which is of great importance in the 
spring bow-pencil as well as in the pen, it is well to 
close the legs nearly together and taking one leg in 



THE DRAWIXG BOARD. 23 

one hand and the other leg in the other hand (between 
the forefinger and thumb), pushing and pulhng them 
sideways, any motion in that direction being sufficient 
to condemn the instrument. It is safest and best to 
have the two legs of the bow-pen and pencil made 
from one piece of metal, and not of two separate 
pieces screwed together at the top, as the screw will 
rarely hold them firmly together. The points should 
be long and fine, and as round as possible. In very 
small instruments separate points that are fastened 
with a screw are objectionable, because, in very small 
circles, they hide the point and make it difficult to ap- 
ply the instrument to the exact proper point or spot 
on the drawinor. 

The joints of the large bow or circle-pen should 
also be somewhat stiff and quite free from side motion, 
and the extension piece should be rigidly secured 
when held by the screw. It is a good plan in purchas- 
ing to put in the extension piece, open the joint 
and the pen to their fullest, and draw a circle, moving 
the pen in one direction, and then redraw it, moving it 
in the other direction, and if one line only appears and 
i.iat not thickened by the second drawing, the pen is a 
good one. 

The lead pencil should be of hard lead, and it is 
recommended that they be of the H, H, H, H, H, H, 
in the English grades, which corresponds to the V, V, 
H, of the Dixon grade. The pencil lines should be 
made as lightly as possible; first, because the presence 
of the lead on the paper tends to prevent the ink 
from passing to the paper ; and, secondly, because in 
rubbing out the pencil lines the ink lines are re- 



24 



MECHANICAL DRA WING SELF- 'lA LGIIT. 




duced in blackness and the surface of the paper be- 
comes roughened, so that it will soil easier and be 
harder to clean. In order to produce fine pencil lines 
without requiring a very frequent 
sharpening of the pencil it is best 
to sharpen the pencil as in Figures 
7 and 8, so that the edge shall be 
long in the direction in which it is 
moved, which is denoted by the 
arrow in Figure 7. But when very 
fine work is to be done, as in the 
case of Patent Office drawings, a 
long, round point is preferable, be- 
cause the eye can see plainer just 
'' '^' ' where the pencil wall begin to 

mark and leave off; hence the pencil lines will not be 
so liable to overrun. 

In place of the ordinary wood-covered lead pencils 
there may be obtained at the drawing material stores 
pencil holders for holding the fine, round sticks of 
lead, and these are by far the best for a learner. They 
are easier to sharpen, and will slip in the holder, giving 
warning when the draftsman is pressing them too hard 
on the paper, as he is apt to do. The best method of 
trimming these leads, as also lead pencils after they 
have been roughly shaped, is with a small fine file, 
holding the file still and moving the pencil; or a good 
piece of emery paper or sand paper is: good, moving 
the pencil as before. 

All lines in pencilling as in inking in should begin at 
the left hand and be drawn towards the right, or when 
trianeles are used the linens are becrun at the bottom 



THE DRAWING BOARD.. 25 

and drawn towards the top or away from the operator. 
The rubber used should not be of a b.arsh grade, since 
that will roughen the face of the paper and probably 
cause the ink to run. The less rubbing out the bet- 
ter the learner will progress, and the more satisfaction 
he will receive from the results. If it becomes neces- 
sary to scratch out it is best done with a penknife 
well sharpened, and not applied too forcibly to the 
paper but somewhat lightly, and moved in different 
and not all in one direction. After the penknife the 
rubber may sometimes be used to advantage, since it 
will, if of a smooth grade, leave the paper smoother 
than the knife. Finally, before inking in, the surface 
that has been scraped should be condensed again by 
rubbing some clean, hard substance over it which will 
prevent the ink from spreading. The end of a paper- 
cutter or the end of a rounded ivory handled drawing 
instrument, is excellent for this purpose. 






Fig. 9. Fig. 10. 

It Is well to use the rubber for general purposes in 
such a w^ay as to fit it for special purposes ; thus, 
in cleaning the sheet of paper, the rubber may be 
applied first, as in Figure 9, as at A, and then as at B, 
and if it be moved sideways at the same time it will 
wear to the form shown in Figure 10, which will enable 
it to be applied along a line that may require to be 
rubbed out without removino- other and neio^hborinof 



25 MECHANICAL DRAWIXG SELF-TAUGHT. 

lines. If the rubber is in the form of a square stick 
one end may be bevelled, as in Figure ii, which is an 





Fig. 12. 

excellent form, or it may be made to have a point, as 
in Figure i 2. The object is in each case to enable 
the rubber action to be confined to the desired loca- 
tion on the paper, so as to destroy its smooth surface 
as little as possible. 

For simple cleaning purposes, or to efface the pen- 
cil lines when they are drawn very lightly, squares of 
sponge-rubber answer admirably, these being fur- 
nished by the dealers in drawing materials. 

A piece of bread will answer a similar purpose, but 
it is less convenient. 

For glazed surface paper, as Bristol-board, the 
smoothest rubber must be used, the grade termed 
velvet rubber answering well. 

THE DRAWING PAPER. 

Whatever kind of drawing paper be used it should 
be kept dry, or the ink, however good it may be, will 
be apt to run and make a thick line that will not have 
the sharp, clean edges necessary to make lines look 
well 

Drawing paper is made in various qualities, kinds, 



THE DRAWIXG BOARD. 



27 



arxd forms, as follows : 


The 


sizes and names 


made in sheets are : 






Cap, 


- 


13x16 inches 


Demy, - 


- 


20x15 * 




Medium, 


- 


22 X 17 ' 




Royal, - 


- 


24 X 19 * 




Super Royal, - 


- 


27 X 19 ' 




Imperial, 


- 


30 X 21 




Elephant, 


- 


28 X 22 ' 




Columbier, 


- 


34x23 ^ 




Atlas, - 


- 


33 X 26 * 




Theorem, 


- 


34 X 28 ' 




Double Elephant, - 


40 X 26 ' 




Antiquarian, - 


- 


52x31 ' 




Emperor, 


- 


40 X 60 ' 




Uncle Sam, - 


- 


48 X 120 





the thickness of the sheets increasing with their 
size. Some sheets of paper are hot pressed, to give a 
smoother surface, and thus enable cleaner-edged lines 
to be drawn. 

For large drawings paper is made in rolls of various 
widths, but as rolled paper is troublesome to lay flat 
upon the drawing board, it is recommended to the 
learner to obtain the sheets, which may be laid suffi- 
ciently flat by means of broad- headed pins, such as 
shown in Figure 13, which are called thumb ^~^ 
tacks. These are forced through the paper ^ 

into the board at each corner, as in Figure Fig. 13. 
14 at/ On account of the large diameter of the 
stems of these thumb tacks, which unduly pierce and 
damage the board, and on account also of their heads, 
bv reason of their thickness, comino- in the wav of the 



28 MECHANICAL DRAWING SELF-TAUGHT. 

square blade, It will be found preferable to use the 
smallest sizes of ordinary iron tacks, with fiat heads, 
whose stems are much finer and heads much thinner 




ng. 14. 

than thumb tacks. The objection to ordinary tacks is 
that they are more difficult to remove, but they are, as 
stated, more desirable for use. 




Fig. 15. 
If the paper is nearly the full size of the board, It 
does not much matter as to its precise location on the 
board, but otherwise It Is best to place It as near the 
left-hand edge of the board as convenient, as Is shown 
in Figure 14. 



THE DRAWING BOARD. 29 

The lower edge, D, Figure 1 5, of the paper, however, 
should not be placed too near the edge, A, of the 
board, because if the end P of the square back comes 
down below the edge of the board, it is more difficult 
to keep the square back true against the end of the 
board. 

The paper must lie flat upon and close to the sur- 
face of the board, and a sufficient number of tacks 
must be used to effect this purpose. 

Drawings that are to be intricate, or to contain a 
great many lines, as a drawing of an engine or of a ma- 
chine, are best pasted or glued all around the edges of 
the paper, which should first be dampened; but as the 
learner will scarcely require to make such drawings 
until he is somewhat familiar with and well practised 
in the use of the instruments, this part of the subject 
need not be treated here. 

TRACING PAPER. 

For taking tracings from drawings tracing paper or 
tracing cloth is used. They require to be stretched 
tightly and without wrinkles upon the drawing. To 
effect this object the mucilage should be thick, and 
the tracing paper should be dampened with a sponge 
after it is pasted. It must be thoroughly dry before 
use, or the ink will run, 

Ti-acing cloth must be fastened by pins or thumb 
tacks, and not dampened. The drawing should be 
made on the polished side of the cloth, and any color- 
ing to be done should be on the other side, and done 
after the tracing is removed from the drawing. 



30 MECHANICAL DRAWING SELF-TAUGHT. 



THE INK. 

India ink should always be used for mechanical 
drawing: First, because it lies upon and does not sink 
into the paper, and is, therefore, easily erased ; and, 
secondly, because it does not corrode or injure the 
drawine instruments. 

India ink is prepared in two forms — in the stick and 
in a liquid form. The stick ink is mixed in what are 
termed saucers, or cabinet saucers, one being placed 
above the other, so as to exclude the dust from set- 
tling in it, and also to prevent the rapid evaporation 
to which it is subject. 

The surface of the saucer should be smooth, as any 
roughness grinds the ink too coarsely, whereas the 
finer it is ground or mixed the easier it will flow, the 
less liability to clog the instruments, and the smoother 
and more flat it will lie upon the paper. In mixing 
the ink only a small quantity of water should be used, 
the stick of ink being pressed lightly upon the saucer 
and moved quickly, the grinding being continued 
until the ink is mixed quite thickly. This will grind 
the ink fine as it is mixed, and more water may be 
added to thin it. It is best, however, to let the ink 
be somewhat thick for use, and to keep it covered 
when not in use ; and though water may be added if 
it gets too thick, yet ink that has once dried should 
not be mixed up again, as it will not work so well 
after having once dried. 

Of liquid inks the Higgins ink is by far the best, 
being quite equal to and much more convenient for 
use than the best stick ink. 



THE DRAWING BOARD. 3 I 

The difference between a good and an inferior India 
ink lies chiefly in die extent to which the lamp-black, 
which is the colorinor matter, forms with the water a 
chemical solution rather than a mechanical mixture. 
In inferior ink the lamp-black is more or less held in 
suspension, and by prolonged exposure to the air will 
separate, so that on being spread the solid particles 
will aggregate by themselves and the w^ater by itself. 

This explains why draughtsmen wall, after the ink 
has been exposed to the air for an hour or two, add a 
drop of mucilage to it ; the mucilage thickening the 
solution, addinor weio-ht to the water, and deferrinof 
the separation of the lamp-black. 

A good India ink is jet black, flows easily, lies close 
to, does not stand upon or sink into the paper, and 
has an even lustre, the latter beincj an indication of 
fineness. The more perfect the incorporation of the 
lamp-black with the water the easier the ink w^ill flow, 
the less liable it is to clog the instruments, the more 
even and sharp the edges of the lines, and the finer 
the lines that may be drawm. 

Usually India ink can only be tested by actual trial; 
but since it is desirable to test before purchasing it, it 
may be mentioned that one method is to mix a litde 
on the finger nail, and if it has a " bronzy " gloss it is 
a good indication. It should also spread out and dry 
without any tendency to separate. 

The best method of testing is to mix a very little, 
and drop a single drop in a tumbler of clear water. 
The best ink will diffuse itself over the surface, and if 
the w^ater is disturbed will difliise itself through the 
water, leaving it translucent and black, with a slight 



^2 MECHANICAL DRAWING SELF-TAUGHT. 

tlnee of bronze color. A coarser ink will act in a 
similar manner, but make the water somewhat opaque, 
with a blue-black, or dull, ashy color. A still coarser 
ink will, when diffused over the surface of the water, 
show fine specks, like black dust, on the surface. This 
is readily apparent, showing that the mixture of the 
ink is not homogeneous. 

When it is an object to have the lines of a drawing 
show as black as possible, as for drawings that are to 
be photo-engraved, the ink should be mixed so thickly 
as to have a tendency to lift when a body, such as a 
lead pencil, is lifted out of it. For Patent Office draw- 
ings some will mix it so thickly that under the above 
test it appears a little stringy. 

The thicker the ink can be used the better, because 
the tendency of the carbon to separate is less ; and it 
is for this reason that the test mentioned with a tum- 
bler of water is so accurate. When ink is to be used 
on parchment, or glossy tracing-paper, it will flow 
perfectly if a few drops of ox-gall be mixed with it ; 
but on soft paper, or on bristol board, this will cause 
the ink to spread. 

For purposes of measurement, there are special 
rules or scales of steel and of paper manufactured. 
The steel rules are finely and accurately divided, and 
some are of triangular form, so that when laid upon 
the paper the lines divided will lie close to the paper, 
and the light will fall directly on the ruled surface. 
Triangular rules or scales are therefore much superior 
to flat Ones. The object of having a paper rule or 
scale is, that the paper will expand and contract under 
varying degrees of atmospheric moisture, the same as 
the drawing paper does. 



THE DRAWING BOARD. 



33 



Figure 1 6 represents a triangular scale, having upon 
it six different divisions of the inch. These are made 



i 1 1 1 1 1 1 1 1 1 1\ m 1 1 1 1 M I hi 

94 92 90 88 8G \ \9 S 7 G 5 4 3 2 1 OV^ 




in different patterns, having either decimal divisions 
or the vulgar fractions. Being made of steel, and 
nickel-plated, they are proof against the moisture of 
the fingers, and are not subject to the variation of 
the wooden scale. 





CHAPTER II. 

THE PREPARATION AND USE OF THE INSTRUMENTS. 

The points of drawing instruments require to be 
very accurately prepared and shaped, to enable them 
to make clean, clear lines. The object is to have the 
points as sharp as they can be made without cutting 
the paper, and the curves as even and regular as pos- 
sible. 

The lining pen should be formed as in Figure 17, 
which presents an edge and a front 
view of the points. The inside 
faces should be flat across, and 
slightly curved in their lengths, as 
Fig. 17. Fig. 18. shown. If this curve is too great, 
as shown exaggerated in Figure 18, the body of the 
ink lies too near the point and is apt to flow too freely, 
running over the pen-point and making a thick, ragged 
line. On the other hand, if the Inside faces, between 
which the Ink lies, are too parallel and narrow near 
the points, the Ink dries In the pen, and renders a too 
frequent cleaning necessary. Looking at the face of 
the pen as at A in Figure 17, its point should have an 
even curve, as shown, the edg^t being as sharp as it 
can be made without cutting the drawing paper. 
Upon this quality depends the fineness and cleanness 
of the lines It will make. This thin edge should ex- 

(34) 



PREPARATION AXD USE OF IXSTRUMEXTS. 35 

tend around the curve as far as the dotted Hne, so 
that it will be practicable to slant the pen in either oi 
the directions shown in Figure 19; and it is obvious 



Fig. 19. Fig. 20. 

that its thickness must be equal around the arc, so 
that the same thickness of line will be drawn whether 
the pen be held vertical or slanted in either direction. 

The outside faces of the pen should be slightly 
curved, so that when held vertically, as in Figure 20 
(the dotted line representing the centre of the length 
of the instrument), and against the square blade S, 
the point will meet -the paper a short distance from 
the lower edge of S as shown. By this means it is 
not necessary to adjust the square edge exactly coin- 
cident with the line, but a little way from it. This is an 
advantage for two reasons : first, the trouble of set- 
ting the square-edge exactly coincident is avoided, and, 
secondly, the liability of the ink to adhere to the edge 
of the square-blade and flow on to the paper and 
make a thick, ragged line, is prevented. 

The square being set as near to the line as desired, 
the handle may be held at such an angle that the pen- 
point will just meet the line when sloped either as in 
Figure 21 or 22. If, however, the slope be too much 
in the direction shown in Figure 21, practice is neces- 
sary to enable the drawing of straight lines if they be 
long ones, because any variation In the angle of the 



36 



MECHANICAL DRAWING SELF-TAUGHT. 



instrument to the paper obviously vitiates the straight- 
ness of the Hne. If, on the other hand, the square be 
too close to the line, and the pen therefore requires 




Fig. 21. Fig. 22. 

to be sloped as in Figure 22, the ink flowing from the 
pen-point is apt to adhere to the square-edge, and the 
result will be a ragged, thick line, as shown in Fig- 
ure 23. 




Fig. 23. Fig. 24. Fig. 25. Fig. 26. 

Each of the legs should be of equal thickness at 
the pen-point edge, so that when closed together the 
point will be in the middle of the edge. The width 
and curve of each individual point should be quite 
equal, and the easiest method of attaining this end is 
as follows : 

Take a small slip of Arkansas oil-stone, and with 
the pen-points closed firmly by the screw trim the pen- 
edges to the required curve as shown at A, Figure 17, 
making the curve as even as possible. Then stone 
the faces until this curve is brought up to a sharp 
edge at the point between the two pen-legs forming 
the point. 



PREPARATION AND USE OF INSTRUMENTS. 37 

Next take a piece of ooo French emery paper, lay 
it upon some flat body like the blade of a square, and 
smooth the curve of the ed^e enouo^h to take off the 
fine, sharp edge left by the oil-stone; then apply the 
outside flat faces of the pen to the emery paper again, 
bringing the pen-edge up sharp. 

The emery paper will simply have smoothed and 
polished the surfaces, still leaving them too sharp, so 
sharp as to cut the paper; and to take off this sharp 
edge (which must first be done on the inside faces) 
open the pen-points as wide as the screw will permit. 
Then wrap one thickness of the emery paper upon a 
thin blade, as upon a drawing-triangle, and pass the 
open pen-points over it, and move the instrument end- 
wise, taking care to keep the inside face level with the 
surface of the emery paper, so that the pen-points shall 
not cut through. Next close the pen-points with the 
screw until they nearly, but not quite, touch, and sweep 
the edge of the pen-point along the emery paper under 
a slight pressure, so moving the handle that at each 
stroke the whole length around the curved end of the 
pen will meet the emery surface. During this motion 
the inside faces of the pen-point must be held as nearly 
vertical as possible, so as to keep the two halves of the 
pen-point equal. 

The pen is now ready for use, and will draw a fine 
and clean line. 

It is not usual to employ emery paper for the pur- 
pose Indicated, but it will be found very desirable, 
since it leaves a smoother surface and ed^e than the 
oil-stone alone. 

Circle-pens are more difficult to put In order than 



^3 MECh-A APICAL DRAWING SELF-TAUGHT. 

the straight-line pen, especially those for drawing the 
smallest circles, which cannot be well drawn unless the 
pen is of the precise right shape and in the best con- 
dition. 

A circle-pen is shown in Figure 24, in which A rep- 
resents the point-leg and B the pen-leg. The point- 
leg must be the longest because it requires to enter 
the drawing paper before the pen meets the surface. 
The point should be sharp and round, for any edges 
or angles on it will cause it to widen the hole in the 
paper when it is rotated. To shape the points to pre- 
vent the enlargement of the centre in the paper is one 
of the most im.portant considerations in the use of this 
instrument, especially when several circles require to 
be drawn from the same centre. To accomplish this 
end the inside of the point-leg should be, as near as 
possible, parallel to the length of the instrument (which 
is denoted in Figure 24 by the dotted line) when the 
legs are closed, as in the figure. If the point is at 
an angle, as shown in Figure 25, it is obvious that 
rotadng it will enlarge the top of the centre in the 
drawing paper. The point should be sharp and smooth 
on its circumferential surface, and so much longer than 
the pen-point that it will have sufficient hold in the 
paper when the instrument stands verUcal and the 
pen-point meets the surface of it, Vv^hich amount is 
about e^th of an inch. 

We may now consider the shape of the pen-point. 
Its inside surfaces should be flat across and to the curve 
shown in Figure 24, not as shown exaggerated in Fig- 
ure 25, because in the latter the body of the ink will 
be too near the pen-point, and but litde can be placed 



PI^EPARATION AND USE OF INSTRUMENTS. oq 

in It without causing It sometimes to flow over the 
edges and down the outside of the pen. 

A form of pen-point recently introduced is shaped 
as in Figure 26, the object being to have a thin stream 
of Ink near the marking pen-point and the main body 
of the ink near at hand, Instead of extending up the 
pen, as would be the case with Figure 24. The ad- 
vantao-e thus oalned is that the ink lies in a more 
solid body, and having less area of surface exposed to 
the air will not dry so quickly In the pen ; but this is 
more than offset by the liability of the Ink to flow over 
the crook at A, and cause the pen to draw a thick 
ragged line. The pen-point must be slightly inclined 
toward the needle-point, to the end that they may ap- 
proach each other close enough for drawing very 
small circles, but it should also stand as nearly verti- 
cal as will permit that end to be attained. As this pen 
is for drawing small circles only, it does not require 
much Ink, and hence may be somewhat close together, 
as In Figure 24 ; this has the advantage that the point 
is not hidden from observation. 

In forming the pen-point the greatest refinement Is 
necessary to enable the drawing of very small true 
circles, say /gth of an Inch, or less, in diameter. The 
requirements are that the pen-point shall meet the 
surface of the paper when the needle-point has en- 
tered it sufficiently to give the necessary support, and 
that the Instrument shall stand vertical, as shown by 
the dotted line in Figure 24. Also, that the pen shall 
then touch the paper at a point only, this point being 
the apex of a fine curve; that this curve be equal on 
each side of the point of contact with the paper; that 



40 



MECHANICAL DRAWING SELF-TAUGHT. 



both halves forming the pen be of equal thickness 
and width at the pointed curve ; and that the point be 
as sharp as possible without cutting- the paper. 

The best method of attaining these ends is as fol- 
lows : On each side of the pen make, with an oil-stone, 
a fiat place, as C D, Figure 27 (where the pen-point 





Figures 27. 28. 29. 30. 31. 32. 

is shov/n magnified), thus bringing both halves to an 
edge of exactly equal length, and leaving the point 
flat at D. These flat places must be parallel to one 
another and to the joint between the two halves of the 
pen. As the oil-stone may leave a slightly ragged 
edge, it is a good plan to take a piece of 00 French 
emery paper, lay it on a flat surface, and holding the 
instrument vertically remove the fine edge D until it 
will not cut. Then with the oil-stone shape the 
curved edge as in Figure 28, taking care that the 
curve no more than brings the flat place D up to a 
true curve and leaves the edge sharp, with only the 
very point touching the paper, which is represented in 
the cut by the horizontal line. 

The point must have a sharp edge all around the 
curve, and the two halves must be exactly equal in 
width, for if one half is wider than the other, as in 
Figure 29 at a, or as in Figure 30 at b, it will be inv 
possible to draw a very small circle true. So, like- 
wise, the two halves of the pen must be of exactly 



PREPARATION AND USE OF INSTRUMENTS. 41 

equal length, and not one half longer than the othen 
as in Figures 31 or 32, which would tend to cut the 
paper, and also render the drawing of true small cir- 
cles impracticable. 

When the pen is closed to draw a very small circle 
the two halves of the pen-leg should have an equal 
degree of contact with the surface of the paper, and 
then as the legs are opened out to draw larger circles 
the contact of the outside half of the pen will have 
less contact with the paper. The smaller the circle, 
the more difficult it is to keep the point-leg from slip- 
ping out of the centre, and the more difficult it is to 
draw a clear line and true circle ; hence the points 
should be shaped to the best advantage for drawing 
these small circles, by oil-stoning the pen, as already 
described, and then finishing it as follows : 

After the oil-stoning, open the two valves of the 
pen-leg wide enough to admit a piece of 000 French 
emery paper wrapped once around a very thin blade, 
and move the pen endwise as described for the 
straight-line pen. This will smooth the inner surfaces 
and remove any fine wire-edge that the oil-stone may 
leave. Close the two halves of the pen again, and 
lightly emery-paper the outside faces, which will leave 
the edge sharp enough to cut the paper. The re- 
moval of the sharp edge still left, to the exact degree, 
requires great care. It may best be done by closing 
the pen until its two halves very nearly, but not quite, 
touch, then adjust it to mark a circle of about /^ inch 
diameter, and strike a number of circles in different 
locations upon the surface of a piece of 0000 French 
emery paper. 



.2 MECHANICAL DRAWING SELF-TAUGHT. 

In marking these circles, however, let the instru- 
ment stand out of the perpendicular, and do very lit- 
tle while standing vertically. Indeed, it is well to strike 
a number of half-circles, first from right to left and 
then from left to right, and finally draw a full circle, 
sloping the pen on one side, gradually raising it verti- 
cally, and finally sloping it to the other side. This will 
insure that the pen has contact at its extreme point, 
and leave that point fine and keen, but not enough so 
to cut the paper. To test the pen, draw^ small circles 
with the pen rotated first in one direction and then in 
the other, closing its points so as to mark a fine line, 
which, if the pen is properly shaped, wdll be clear and 
fine, while if improperly formed the circle drawn with 
the pen rotated in one direction will not coincide with 
that drawn wdiile rotating it in the other. The same 
circle may be drawn over several times to make a 
thorough test. If a drawing instrument will draw a 
fine line correctly, it will be found to answer for thick 
lines which are more easily made. 

In thus preparing the instruments, the operator will 
find that if he occasionally holds the points in the 
right position with regard to the light, he will be able 
to see plainly if the work is proceeding evenly and 
equally, for if one-half of the pen is thicker at the 
point or edge than the other, it will show a brighter 
line. This is especially the case with instruments that 
have become dull by use, for in that case the edges 
will be found quite bright, and any inequality of thick- 
ness shows plainly. 

It follows, from what has been said, that the needle- 
point and pen-point should stand vertical when in use, 



PREPARATION AND USE OF INSTRUMENTS. 43 

and to effect this the instruments, except in the 
smallest sizes, are provided with joints, such as shown 



at A and B in the bow-pencil or circle-pencil, in Fig- 
ure 2)0' These joints should be sufficiently stiff that 





Fig. ZZ' • Fig. 34. 

they wdll not move too easily, and yet will move rather 
than that the legs should sensibly spring without 
m_oving at the joint. The needle-point leg should be 
adjusted by means of the joint, to stand vertical, 
and the same remarks apply equally to the pen- 
leg ; but in' the case of the pencil-leg it is the pen- 
cil itself and not the leg that requires attention, 
the joint B being so adjusted that the pencil either 
stands vertical, or, what is perhaps preferable, so that 



44 



MECHANICAL DRAWING SELF-TAUGHT. 



it stands inclined slightly towards the needle-point. 
In sharpening the pencil the inner face C may be made 
concave or at least vertical and fiat, and the outer con- 
'"^x or else bevelled and fiat, producing a fine and long 
..ore rounded in its lenorth of ed^e. In usino^ the circle- 
pencil and circle-pen it will be found more convenient 
to rotate it in the direction of the arrow in Figure 34. 
It should be held lightly to the paper, and the learner will 
find that he has a natural tendency to hold it too firmly 
and press it too heavily, which is especially to be avoided. 
If in drawing a small circle the needle-point slips 
out of the paper, it is because the pencil-point is too 
long ; or, what is the same thing, the needle-point does 
not protrude far enough out from the leg. Or if the 
instrument requires to be leaned over too much to 
make the pencil or pen mark, it is because the pen or 
pencil is not far enough out, and this again may cause 
the needle-point to slip out of the paper. 




Fig. 35- 



In Figure 35 is shown a German instrument espec- 



PREPARATION AND USE OF INSTRUMENTS. ^^ 

ially designed to avoid this slipping. The pecuharity 
of this instrument consists in the arrangement of the 
centre point, which remains stationary whilst the pen 




Fig. ^(,. 



or pencil, resting by its own weight on the paper, is 
guided round by gently turning, without pressure, 
the small knob at the upper end of the tube. By this 



^5 MECHANICAL DRAIVIXG SELF-TAUGHT. 

means the misplacing or sliding of the centre-point 
and the cutting of the paper by the pen are avoided. 
By means of this fixed centre-point any number ^j{ 
concentric circles may be drawn, without making' a 
hole of very distinguishable size on the paper. 




Fig. 37- 
In applying the ink to the bow-pen as to all other 
instruments, care must be taken that the ink lies be- 
tween the points only and not on the outside, for in 
the latter case the ink will flow down too freely and 
make a broad, ragged line, perhaps getting on the 
edge of the square blade or triangle, and causing a 
blot of ink on the drawino-. 



PREPARATION AND USE OF INSTRUMENTS. ^-j 

In using a straight line or lining pen with a T 
square it may be used as in Figure 36, being nearly 
vertical, as shown, and moved from left to right as de- 
noted by the arrow, S representing the square blade. 
But in using it, or a pencil, with a straight edge or a 
triangle unsupported by the square blade, the latter 
should be steadied by letting the fingers rest upon it 
while using the instrument, the operation being shown 
in Figure ^il- The position, Figure 36, is suitable for 
long lines, and that in Figure 37 for small drawings, 
where the pen requires close adjustment to the lines. 



CHAPTER III. 
LINES AND CURVES. 

Although the beginner will find that a study of 
geometry is not essential to the production of such 
elementary examples of mechanical drawing as are 
given in this book, yet as more difficult examples are 
essayed he will find such a study to be of great ad- 
vantage and assistance. Meantime the followine ex- 
planation of simple geometrical terms is all that is 
necessary to an understanding of the examples given. 

The shortest distance between two points is termed 
the radius; and, in the case of a circle, means the dis- 
tance from the centre to the perimeter measured in a 
straicrht line. 

Dotted lines, thus, < >, mean the direction and 




Fig. 39- 



Fig. 40. 



the points at which a dimension is taken or marked. 

Dotted lines, thus, , simply connect the same 

parts or lines in different views of the object. Thus in 
(48) 



LINES AND CURVES. 



49 



Figure 38 are a side and an end view of a rivet, and die 
dotted lines show that the circles on the end view 
correspond to the circle of the diameters of the head 
and of the stem, and therefore represent their diame- 
ters while showing that both are round. A straiglit 
line is in cr^ometrv termed a rieht line. 

A line at a right angle to another is said to be per- 
pendicular to it; thus, in Figures 39, 40, and i^\, lines 
A are in each case perpendicular to line B, or line B 
is in each case perpendicular to line A. 

A point is a position or location supposed to have 




Fig. 41. Fig. 42. Fig. 43. 

no size, and in cases where necessary is indicated by 
a dot. 

Parallel lines are those equidistant one from the 
other throughout their length, as in Figure 42. Lines 

B\ ■ 7A 



/ 



\ / 



Fig. 44. Fig. 45. Fig. 46. 

maybe parallel though not straight; thus, in Figure 43^ 
the lines are parallel. 
4 



to 



MECHAXICAL DRAWIXG SELF-TAUGHT. 



A line is said to be prochtccd when it is extended 
beyond its natural limits: thus, in Figure 44, lines A 
and B are prodiued in the point C. 

A line is bisected when the centre of its leneth is 
marked: thus, line A in Figure 45 is bisected, at or in, 
as it is termed, e. 

The line bounding a circle is termed its circumfer- 
ence of periphery and sometimes the perimeter. 

A part of this circumference is termed an arc of a 
circle or an arc; thus Figure 46 represents an arc. 




\. 



Fig. 47. 



48. 



Yn 



49. 



When this arc has breadth it is termed a segment; 
thus Figures 47 and 48 are segments of a circle. A 
straight line cutting off an arc is termed the chord of 





Fig. 50. Fig. 51. 

the arc; thus, in Figure 48, line A is the chord of the 



arc. 



A quadrant of a circle is one quarter of the same, 



LIXJES AA'D CURVES. 



being bounded on two of its sides by two radial lines, 
as in Figure 49. 

When the area of a circle that is enclosed within 
two radial lines is either less or more than one quar- 
ter of the whole area of the circle the figure is termed 
a sector; thus, in Figure 50, A and B are both sectors 
of a circle. 

A straight line touching the perimeter of a circle is 
said to be tangent to that circle, and the point at 
which it touches is that to which it is tangent; thus, in 
Figure 51, line A Is tangent to the circle at point B. 
The half of a circle is termed a semicircle; thus, in 
Figure 52, A B and C are each a semicircle. 




■e 



Fig. 52. 



Fig. 53- 



The point from which a circle or arc of a circle is 
drawn is termed its centre. The line representing the 
centre of a cylinder is termed its axis ; thus, in Figure 
53, dot d represents the centre of the circle, and line 
b b the axial line of the cylinder. 

To draw a circle that shall pass through any three 
given points : Let A B and C in Figure 54 be the 
points through which the circumference of a circle is 
to pass. Draw line D connecting A to C, and line E 
connecting B to C. Bisect D in F and E in G. From 
F as a centre draw the semicircle O, and from G as 
a centre draw the semicircle P ; these two semicircles 
meeting the two ends of the respective lines D E. 



52 



MECHANICAL DRAWING SELF-TAUGHT. 



From B as a centre draw arc H, and from C the arc 
I, bisecting P in J. From A as a centre draw arc K, 
and from C the arc L, bisecting the semicircle O in 
M 





P 

Fig. 54- 

M. Draw a line passing through M and F, and a line 
passing through J and Q, and where these two lines 
intersect, as at Q, is the centre of a circle R that will 
pass through all three of the points A B and C. 

To find the centre from which an arc of a circle 
has been struck : Let A A in Figure 55 be the arc 
whose centre is to be found. From the extreme ends 
of the arc bisect it in B. From end A draw the arc 
C, and from B the arc D. Then from the end A 
draw arc G, and from B the arc F. Draw line H 
passing through the two points of intersections of 
arcs C D, and line I passing through the two points 
of intersection of F G, and where H and I meet, as 
at J, is the centre from which the arc was drawn. 

A degree of a circle is the 3^^ part of its circum- 
ference. The whole circumference is supposed to be 
divided into 360 equal divisions, which are called the 



LINES AND CURVES. 



53 



degrees of a circle ; but, as one-half of the circle is 
simply a repetition of the other half, it is not neces- 
sary for mechanical purposes to deal with more than 
one-half, as is done in Figure 56. As the whole 
circle contains 360 degrees, half of it will contain 
one-half of that number, or 180; a quarter will 
contain 90, and an eighth will contain 45 degrees. 
In the protractors (as the instruments having the 
degrees of a circle marked on them are termed) 
made for sale the edcres of the half-circle are marked 




isa 



off into decrees and half-deerees ; but it is sufficient 
for the purpose of this explanation to divide off one 
quarter by lines 10 degrees apart, and the other by lines 
5 degrees apart. The diameter of the circle obviously 
makes no difference in the number of degrees con- 
tained in any portion of it. Thus, in the quarter 
from o to 90, there are 90 degrees, as marked ; but 
suppose the diameter of the circle were that of inner 
circle d, and one-quarter of It would still contain 90 
degrees. 



54 



MECHANICAL DRAWING SELF-TAUGHT, 



So, likewise, the degrees of one line to another are 
not always taken from one point, as from the point o, 
but from any one line to another. Thus the line 
marked 120 is 60 degrees from line 180, or line 90 is 
60 degrees from line 150. Similarly in the other 
quarter of the circle 60 degrees are marked. This 
may be explained further by stating that the point 
o or zero may be situated at the point from which the 
degrees of angle are to be taken. Here it may be 
remarked that, to save writing the word " degrees," 
it is usual to place on the right and above the figures 
a small °, as is done in Figure 56, the 60° meaning 
sixty degrees, the °, of course, standing for degrees. 

Suppose, then, we are given two lines, as a and b in 
Figure 57, and are required to find their angle one to 




Fig. 57- 

the other. Then, if we have a protractor, we may 
apply it to the lines and see how many degrees of 
angle they contain. This word " contain " means how 
many degrees of angle there are between the lines, 



LINES AND CURVES. 



55 



which, in the absence of a protractor, we may find by 
prolonging the Hnes until they meet in a point as at c. 
From this point as a centre we draw a circle D, pass- 
ing through both lines a, b. All we now have to do is 
to find what part, or how much of the circumference, of 
the circle is enclosed within the two lines. In the ex- 
ample we find it is the one-twelfth part ; hence the 
lines are 30 degrees apart, for, as the wdiole circle 
contains 360, then one-twelfth must contain 30, be- 
cause 360-^12=30. 

If we have three lines, as lines A B and C in 
Figure 58, we may find their angles one to the other 




Y.^. 58. 



by projecting or prolonging the lines until they meet 
as at points D, E, and F, and use these points as the cen- 
tres wherefrom to mark circles as G, H, and I. Then, 
from circle H, we may, by dividing it, obtain the angle 



^5 MECHANICAL DRAWIXG SLLF-TAUGHT. 

of A to B or of B to A. By dividing circle I we may 
obtain the angle of A to C or of C to A, and by 
dividing circle G we may obtain the angle of B to C 
or of C to B. 

It may happen, and, indeed, generally will do so, 
that the first attempt will not succeed, because the 
distance between the lines measured, or the arc of 
the circle, will not divide the circle without having the 
last division either too lono- or too short, in which 
case the circle may be divided as follows : The com- 
passes set to its radius, or half its diameter, will 
divide the circle into 6 equal divisions, and each of 
these divisions will contain 60 degrrees of anele, be- 
cause 360 (the number of degrees in the whole 
circle) -v-6 (the number of divisions) =60, the number 
of decrees in each division. We mav, therefore, 
subdivide as many of the divisions as are necessary 
for the two lines whose deo^rees of ancrle are to be 

o o 

found. Thus, in Figure 59, are two lines, C, D, and 




it is required to find their angle one to the other. 
The circle is divided into six divisions, marked re- 
spectively from I to 6, the division being made from 



LINES AXD CURVES. 



57 



the intersection of line C with the circle. As both lines 
fall within less than a division, we subdivide that 
division as by arcs a, b, which divide it into three 
equal divisions, of which the lines occupy one division. 
Hence, it is clear that ihey are at an angle of 20 
degrees, because twenty is one-third of sixty. When 
the number of degrees of angle between two lines 
is less than 90, the lines are said to form an acute 
angle one to the other, but when they are at more 
than 90 degrees of angle they are said to form an 
obtuse ancrle. Thus, in Picture 60, A and C are at 




an acute angle, while B and C are at an obtuse angle. 
F and G form an acute angle one to the other, as also 
do G and B, while H and A are at an obtuse angle. 
Between I and J there are 90 degrees of angle ; 
hence they form neither an acute nor an obtuse 
angle, but what is termed a right-angle, or an angle 
of 90 degrees. E and B are at an obtuse angle. 
Thus it will be perceived that it is the amount of in- 
clination of one line to another that determines its 



eg MECHANICAL DRAWING SELF-TAUGHT. 

angle, irrespective of the positions of the lines, with 
respect to the circle. 

TRIANGLES. 

A ricrht-anorled triano^le is one in which two of the 
sides are at a riorht ano^le one to the other. Fissure 
6i represents a right-angled triangle, A and B forming 



i/ 


/ 


i/c 


A 


/ B 





Right angle 
Triangle 



Obtxjbs^ angle 
Triangle 



Base 
Fig, 6l. 




Fig. 62. 



a right angle. The side opposite, as C, is called the 
hypothenuse. The other sides, A and B, are called 
respectively the base and the perpendicular. 



Equilateral 
Triangle 



Isoceles Triangle 





Base 



Fig. 64. 

An acute-angled triangle has all Its angles acute, 
as in Figure 63. 

An obtuse-angled triangle has one obtuse angle, as 
A, Figure 62. 



LIXES AND CURVES. 



59 



When all the sides of a triangle are equal in 
length and the angles are all equal, as in Figure 
63, it is termed an equilateral triangle, and either 
of its sides may be called the base. When two 
only of the sides and two only of the angles are 
equal, as in Figure 64, it is termed an isosceles triangle, 
and the side that is unequal, as A in the figure, is 
termed the base. 



Scalene 
Triangle 





Fig. 65. 

When all the sides and angles are unequal, as in 
Figure 65, it is termed a scalene triangle, and either 
of its sides may be called the base. 

The angle opposite the base of a triangle is called 
the vertex. 



Fig. 67. 



JRhomb 

Fig. 6^. 



A figure that is bounded by four straight lines is 
termed a quadrangle, quadrilateral or tetragon. 
When opposite sides of the figure are parallel to each 



5o MECHANICAL DRAWING SELF-TAUGHT. 

Other it is termed a parallelogram, no matter what 
the angle of the adjoining lines in the figure may be. 
When all the angles are right angles, as in Figure 66, 
the figure is called a rectangle. If the sides of a 
rectangle are of equal length, as in Figure 67, the 
figure is called a square. If two of the parallel sides 
of a rectanele are longrer than the other two sides, as 
in Figure 66, it is called an oblon<^. If the lencrth 
of the sides of a parallelogram are all equal and 
the angles are not right angles, as in Figure 68, it 
is called a rhomb, rhom^bus or diamond. If two 
of the parallel sides of a parallelogram are longer 
than the other two, and the angles are not right 




B'^'om'bnUl 



Trapezoid trapezium 

Fig. 69. Fig. 70. Fig, 71. 

angles, as in Figure 69, it is called a rhomboid. 
If two of the parallel sides of a quadrilateral are of 
unequal lengths and the angles of the other two 
sides are not equal, as in Figure 70, it is termed a 
trapezoid. 

If none of the sides of a quadrangle are parallel, 
as in Figure 71, it is termed a trapezium. 



LINES AND CURVES. 



6i 



THE CONSTRUCTION OF POLYGONS. 

The term polygon Is applied to figures having fiat 
sides equidistant from a common centre. From this 
centre a circle may be struck that will touch all the 
corners of the sides of the polygon, or the point of 
each side that Is central in the length of the side. In 
drawing a polygon, one of these circles is used upon 
w^hlch to divide the figure Into the requisite number 
of divisions for the sides. When the dimension of 
the polygon across its corners is given, the circle 





Fig. 71 a. Fig. 72. 

drawn to that dimension circumscribes the polygon, 
because the circle is without or outside of the polygon 
and touches it at its corners only. When the dimen- 
sion across the flats of the polygon is given, or w^hen 
the dimension given is that of a circle that can be 
Inscribed or marked within the polygon, touching its 
sides but not passing through them, then the polygon 
circumscribes or envelops the circle, and the circle is 
inscribed or marked within the polygon. Thus, in 
Figure 71 a, the circle is inscribed wltbiin the polygon, 
w^hlle in Figure 72 the polygon Is circumscribed by 
the circle; the first is therefore a circumscribed and 



62 



ME CHA NIC A L DRAW 'IXG SEL F- TA UG II T. 



the second an inscribed polygon. A regular poly 



length. 






NAMES OF 


REGULAR POLYGONS. 


A figure of 3 


sides is 


called a Trigon. 


4 




'^ Tetragon. 


polygon 5 




" Pentagon. 


6 




, ^' Hexagon. 


7 




'' Heptagon. • 


8 




^' Octagon. 


9 




*' Enneagon or Nonagon 



The angles of regular polygons are designated by 
their degrees of angle, "at the centre" and "at the 
circumference." By the angle at the centre is meant 
the angle of a side to a radial line ; thus in Figure J2> 





Fig. 73- Fig. 74. 

is a hexagon, and at C is a radial line; thus the angle 
of the side D to C is 6o degrees. Or if at the two 
ends of a side, as A, two radial lines be drawn, as B, 
C, then the angles of these two lines, one to the other, 
will be the "angle at the centre." The angle at the 
circumference is the angle of one side to its next 
neighbor; thus the angle at the circumference in a 
hexagon is 120 degrees, as shown in the figure for 



LINES AND CURVES. 63 

the sides E, F. It is obvious that as all the sides are 
of equal length, they are all at the same angle both 
to the centre and to one another. In Figure 74 is a 
trio^on, the ancrles at its centre beino- 1 20, and the 
anele at the circumference beinor 50, as marked. 
The angles of regular polygons : 

Trigon, at the centre, 120°, at the circumference, 60°. 

Tetragon, " 90^, '' " 90°, 

Pentagon, " 72°, '' '' 108° 

Hexagon, " 60°, '' " 120° 

Octagon, '' 45°. " " 135° 

Enneagon, " 40^, " " 140° 

Decagon, '' 36°, '' " 144° 

Dodecagon, " 30°, '' " 150° 



An ellipse is a figure bounded by a continuous 
curve, whose nature will be shown presently. 

The dimensions of an ellipse are taken at its ex- 
treme length and narrowest width, and they are des- 
ignated in three ways, as by the length and breadth, 
by the major and minor axis (the major axis meaning 
the length, and the minor the breadth of the figure)^ 
and the conjugate and transverse diameters, the trans- 
verse meaning the shortest, and the conjugate the 
longest diameter of the figure. 

In this book the terms major and minor axis will 
be used to designate the dimensions. 

The minor and major axes are at a right angle one 
to the other, and their point of intersection is termed 
the axis of the ellipse. 

In an ellipse there are two points situated upon the 



54 MECHANICAL DRAWING SELF-TAUGHT. 

line representing the major axis, and which are termed 
the foci when both are spoken of, and a focus when 
one only is referred to, foci simply being the phiral 
of focus. These foci are equidistant from the centre 
of the elHpse, which is formed as follows: Two pins 
are driven in on the major axis to represent the foci A 
and B, Figure 75, and around these pins a loop of 




Fig. 75' 

fine twine is passed ; a pencil point, C, is then placed 
in the loop and pulled outwards, to take up the slack 
of the twine. The pencil is held vertical and moved 
around, tracing an ellipse as shown. 

Now it is obvious, from this method of construction, 
that there will be at every point in the pencil's path a 
length of twine from the final point to each of the foci, 
and a lencrth from one foci to the other, and the length 
of twine in the loop remaining constant, it is demon- 
strated that if in a true ellipse we take any number 
of points in its curve, and for each point add together 
its distance to each focus, and to this add the distance 
apart of the foci, the total sum obtained will be the 
same for each point taken. 



LINES AND CURVES. 



6s 



In Figures 76 and ^"j are a series of ellipses marked 
with pins and a piece of twine, as already described. 
The corresponding ellipses, as A in both figures, were 




Fig. 76. 



Fig- 77- 



marked with the same loop, the difference in the two 
forms being due to the difference in distance apart of 
the foci. Again, the same loop was used for ellipses 
B in both fio-ures, as also for C and D. From these 
figures we perceive that — 

I St. With a given width or distance apart of foci, 
the larorer the dimensions are the nearer the form of 
the figure will approach to that of a circle. 

2d. The nearer the foci are together in an ellipse, 
having any given dimensions, the nearer the form of 
the figure will approach that of a circle. 

3d. That the proportion of length to width in an 
ellipse is determined by the distance apart of the foci. 

4th. That the area enclosed within an ellipse of a 
given circumference is greater in proportion as the 
distance apart of the foci is diminished ; and, 
5 



66 



MECHAXICAL DRA U'lXG SELF- TA UGHT. 



5th. That an ellipse may be given any required 
proportion o{ width to length by locating the foci at 
the requisite distance apart. 

The form of a true ellipse may be very nearly ap^ 
proached by means of the arcs of circles, if the centres 
from which those arcs are struck are located in the 
most desirable positions for the form of ellipse to be 
drawn. 

Thus in Figure ^"^ are three ellipses whose forms 




78. 

were pencilled in by means of pins and a loop of twine, 
as already described, but wliich were inked in by find- 
ing four arcs of circles of a radius that would most 
closely approach the pencilled line ; a b are the foci 
of all three ellipses A, B, and C ; the centre for the 
end curves of a are at c and d, and those for its side 
arcs are at c and f. For B the end centres are at ^;^ 
and //, and the side centres at / and/. For C the end 
centres are at /', /, and the side centres at vi and n. 



LIiVES AND CURVES. 



67 



It will be noted that, first, all the centres for the end 
curves fall on the line of the length or major axis, 
while all those for the sides fall on the line of width 
or the minor axis; and, second, that as the dimensions 
of the ellipses increase, the centres for the arcs fall 
nearer to the axis of the ellipse. Now in proportion 
as a greater number of arcs of circles are emplo3^ed 
to form the figure, the nearer it will approach the 
form of a true ellipse ; but in practice it is not usual 
to employ more than eight, while it is obvious that 
not less than four can be used. When four are used 
they will always fall somewhere on the lines on the 
major and minor axis ; but if eight are used, two will 




Fig. 79. 

fall on the line of the major axis, two on the line of 
the minor axis, and the remaining four elsewhere. 

In Figure 79 is a construction wherein four arcs are 
used. Draw the line a b, the m.ajor axis, and at a 



5S MECHANICAL DRAWING SELF-TAUGHT. 

right angle to it the Hne c d, the minor axis of the 
fieure. Now find the difference between the ienorth 
of half the two axes as shown below the figure, the 
length of line / (from g to i) representing half the 
length of the figure (as from a to e), and the length 
or radius from g lo h equalling that from ^ to d ; 
hence from h to i is the difference between half the 
major and half the minor axis. With the radius (hi)y 
mark from ^ as a centre the arcs/^, and join / k by 
line /. Take half the length of line / and from j as a 
centre mark a line on a to the arc m. Now the radius 
of m from e will be the radius of all the centres from 
which to draw the figure ; hence we may draw in the 
circle m and draw line s, cutting the circle. Then draw 
line o, passing through in, and giving the centre /. 
From p we draw the line q, cutting the intersection of 
the circle with line a and giving the centre r. From 
r we draw line s, meeting the circle and the line c, d, 
giving us the centre t. From t we draw line it, pass- 
ing through the centre m. These four lines o, q, s, u 
are prolonged past the centres, because they define 
what part of the curve is to be drawn from each 
centre : thus from centre ni the curve from v \.o w \s> 
drawn, from centre t the curve from zv to x is drawn. 
From centre r the curve from x toj/is drawn, and 
from centre / the curve from y to v is drawn. It is 
to be noted, however, that after the point 7n is found, 
the remaining lines may be drawn very quickly, be- 
cause the line o from m to / may be drawn with the 
triangle of 45 degrees resting on the square blade. 
The triangle may be turned over, set to point p and 
line q drawn, and by turning the triangle again the 



LIA'ES AND CURVES. 5q 

line s may be drawn from point r ; finally the triangle 
may be again turned over and line u drawn, which 
renders the drawing of the circle m unnecessary. 

To draw an elliptical figure whose proportion of 
width to breadth shall remain the same, whatever the 
length of the major axis may be : Take any square 
figure and bisect it by the line A in Figure 80. Draw, 




in each half 01 the square, the diagonals E F, G H. 
From P as a centre with the radius P R draw the 
arc S E R. With the same radius draw from O as 
a centre the arc T D V. With radius L C draw 
arc R C V, and from K as a centre draw arc S B T. 

A very near approach to the true form of a true 
ellipse may be drawn by the construction given in 
Figure 81, in which A A and BB are centre lines 
passing through the major and minor axis of the 
ellipse, of which a is the axis or centre, b c\s the major 
axis, and ae half the minor axis. Draw the rectangle 
bfgc, and then the diagonal line be; at a right angle 
to ^ ^ draw \inQ//i, cutting B B at z. With radius a e 
and from ^ as a centre draw the dotted arc ej, giving 



^O MECHANICAL DRAWING SELF-TAUGHT. 

the point / on line B B. From centre k, which is on 
the h*ne B B and central between b and j, draw the 
semicircle b m j\ cutting A A at /. Draw the radius 




A 

Fig. 8 1. 

of the semicircle binj, cutting it at ;;^, and cutting^^ 
at n. With the radius vi n mark on A A at and from 
.7 as a centre the point o. With radius h o and from 



LIXES AXD CURVES. 



71 



centre k draw the arc p q. With radius a I and from 
b and c as centres, draw arcs cutting^ q 2X the points 
p q. Draw the Hnes k p r and h q s and also the lines 
pit and q v w. From h as a centre draw that part 
of the ellipse lying between rand s, with radius/ r ; 
from j2^ as a centre draw that part of the ellipse lying 
between r and t, with radius q s ; and from ^ as a centre 
draw the ellipse from s to w, with radius i t ; and from i 
as a centre draw the ellipse from tX.o b and with radius 




V w, and from z^ as a centre draw the ellipse from lo 
to c, and one-half of the ellipse will be drawn. It will 
be seen that the whole construction has been per- 
formed to find the centres h,p, q, /and z\ and that while 

V and i may be used to carry the curve around on the 
other side of the ellipse, new centres must be pro- 
vided for h p and q, these new centres corresponding 
in position to /// q. Divesting the drawing of all the 



7- 



ME CHANICA L DRA WIXG SEL F- TA UGII T. 



lines except those determining its dimensions and the 
centres from which the elhpse is struck, we have in 
Figure '^2 the same elhpse drawn half as large. The 
centres v, p, q, h correspond to the same centres in Fig- 
ure 81, while v\ p\ q', /^'are in corresponding positions 
to draw in the other half of the ellipse. The length of 
curve drawn from each centre is denoted by the dotted 
lines radiating from that centre ; thus, from k the part 
from r to i- is drawn ; from h' that part from 1^ to y. At 
the ends the respective centres v are used for the parts 
from iv tozn/ and from t to /' respectively. 

The most correct method of drawing an ellipse is 
by means of an instrument termed a trammel, which is 
shown in Figure 83. It consists of a cross frame in 

B 




which are two grooves, represented by the broad black 
lines, one of which is at a right angle to the other. 
In these grooves are closely fitted two sliding blocks, 
carrying pivots E F, which may be fastened to the 
sliding blocks, while leaving them free to slide in the 
grooves at any adjusted distance apart. These blocks 
carry an arm or rod having a tracing point (as pen or 
pencil) at G. When this arm is swept around by the 



LAVES AXD CURVES. 



73 



operator, the blocks slide in the grooves and the pen- 
point describes an ellipse whose proportion of width 
to length is determined by the distance apart of the 
sliding blocks, and whose dimensions are determined 
by the distance of the pen-point from the sliding block. 
To set the instrument, draw lines representing the 
major and minor axes of the required ellipse, and set 
off on these lines (equidistant from their intersection), 
to mark the required length and width of ellipse. 
Place the trammel so that the centre of its slots is 
directly over the point or centre from which the axes 
are marked (which may be done by setting the centres 
of the slots true to the lines passing through the axis) 
and set the pivots as follows: Place the pencil-point 
G so that it coincides with one of the points as C, and 
place the pivot E so that it comes directly at the point 
of intersection of the two slots, and fasten it there. 
Then turn the arm so that the pencil-point G coincides 
with one of the points of the minor axis as D, the arm 
lying parallel to B D, and place the pivot F over the 
centre of the trammel and fasten it there, and the 
setting is complete. 




Fig. 84. 

To draw a parabola mechanically: In Figure 84 
C D is the width and H J the height of the curve. 



MECHAXICAL DRAWING SELF-TAUGHT. 



Bisect H D in K. Draw the diagonal line J K and 
draw K E, cutting K at a right angle to J K, and pro- 
duce it in E. With the radius H E, and from J as a 
centre, mark point F, which will be the focus of the 
curve. At any convenient distance above J fasten a 
straight-edge A B, setting it parallel to the base C D 
of the parabola. Place a square S with its back 
against the straight-edge, setting the edge O N coin- 
cident with the line J H. Place a pin in the focus F, and 
tie to it one end of a piece of twine. Place a tracing- 
point at J, pass the twine around the tracing-point, bring- 
ing down along the square-blade and fasten it at N, with 
the tracing-point kept against the edge of the square 
and the twine kept taut ; slide the square along the 
straight-edge, and the tracing-point will mark the half 
J C of the parabola. Turn the square over and 
repeat the operation to trace the other half J D. 
This method corresponds to the method of draw- 
ing an ellipse by the twine and pins, as already de- 
scribed. 

To draw a parabola by lines : Bisect the width A B 
in Figure 85, and divide each half into any convenient 

c 






J2345654323 

Fig. 85. 

number of equal divisions; and through these points 
of division draw vertical lines, as i, 2, 3, etc. (in each 
half). Divide the height A D at one end and B E at 
the other into as many equal divisions as the half of 



LINES AND CURVES. 



7S 



A B Is divided into. From the points of divisions i, 
2, 3, etc., on lines A D and B E, draw lines pointing to 
C, and where these lines Intersect the corresponding- 
vertical lines are points through which the curve may 
be drawn. Thus on the side A D of the curve, the 
Intersection of the two lines marked i Is a point in the 
curve ; the intersection of the two lines marked 2 is 
another point in the curve, and so on. 

TO DRAW A HEART CAM. 

Draw the line A B, Figure ^6, equal to the length 
of stroke required. Divide It Into any number of 




equal parts, and from C as a centre draw circles 
through the points of division. Draw the outer circle 
and divide Its circumference Into twice as many equal 
divisions as the line A B was divided Into. Draw 
radial lines from each point of division on the circle, 
and the points of intersection of the radial lines with 
the circles are points for the outline of the cam, and 



^5 MECHANICAL DRAWING SELF-TAUGHT. 

through these points a curve is drawn giving the 
pitch line of the cam, from which the proper shape of 
the cam may be drawn as follows ; 




Fig. 86 A. 



In Figure %6 A we have this pitch line, and at R 
the roller for the cam, a pair of compasses are set to 
the radius of the roller, and from a number of points 
on the pitch line A B, as at E, F, arcs of circles are 
drawn, and touching these arcs a line may be drawn 
representing the actual or proper outline of the cam. 
It being borne in mind that with the same pitch line a 
different form of cam will be required for every 
different diameter of roller R, and that the larger the 
roller R, the easier and the fester the cam will run 
without knock or jar. 



CHAPTER IV. 
SHADOW LINES AND LINE SHADING, 

SECTION LINING OR CROSS-HATCHING. 

When the Interior of a piece is to be shown as a 
piece cut in half, or when a piece is broken away, as is 
done to make more of the parts show, or show more 
clearly, the surface so broken away or cut off is sec- 
tion-lined or cross-hatched ; that is to say, diagonal 




Fig. 87. 

lines are drawn across it, and to distinguish one piece 
from another these lines are drawn at varying angl-^s 
and of varying widths apart. In Figure Sj is given a 
view of three cylindrical pieces. It may be known to 
be a sectional view by the cross-hatching or section 
lines. It would be a difficult matter to represent the 
three pieces put together without showing them in 
section, because, in an outline view, the collars and re- 
ly?) 



/-s 



iMECHAXICAL DRAIVIXG SELF-TAUGHT. 



cesses would not appear. Each piece could of course 
be drawn separately, but this would not show how they 
were placed when put together. They could be shown 
in one view if they w^ere shaded by lines and a piece 
shown broken out where the collars and recesses are, 
but line shading^ is too tedious for detail drawings, 
beside involving too much labor in their production. 

Figure Z'^ represents a case in which there are 
three cylindrical pieces one within the other, the two 





Fig. 89. 

inner ones being fastened together by a screw which 
is shown dotted in in the end view, and whose position 
along the pieces is shown in the side view. The 
edges of the fracture in the outer piece are in this case 
cross-hatched, to show the line of fracture. 

In cross-hatching it is better that the diagonal lines 
do not quite meet the edges of the piece, than that 
they should in the least overrun, as is shown in Fig. 
ure 89, where in the top half the diagonals slightly 
overrun, while in the lower half they do not quite 
meet the outlines of the piece. 

In Figure 90 are shown in section a number of 
pieces one within the other, the central bore being 



SHADOW LINES AXD LIXE SHADING. 



79 



filled witli short plugs. All the cross-hatching was 
done with the triangle of 60 degrees and that of go 
degrees. It is here shown that with these two tri- 
angles only, and a judicious arrangement of the di- 




agonals, an almost infinite number of pieces may be 
shown in cross section without any liability of mistak- 
ing one for the other, or any doubt as to the form and 
arrangement of the pieces ; for, beside the difference 
in spacing in the cross-hatching, there are no two ad- 
joining pieces with the diagonals running in the same 
direction. It will be seen that the narrow pieces are 
most clearly defined by a close spacing of the cross- 
hatching. 

In Figure 91 are shown three pieces put together 
and having slots or keyways through them. The 
outer shell is shown to be in one piece from end to 
end, because the cross-l;atching is not only equally 
spaced, but the diagonals are in the same direction ; 
hence It would be known that D, F, H, and E were 
slots or recesses through the piece. The same re- 
marks apply to piece B, wherein G, J, K are recesses 



4 



8o 



MECHANICAL DRAWING SELF-TAUGHT. 



or slots. Piece C is shown to have in its bore a recess 
at L. In the case of B, as of A, there would be no 
question as to the piece being all one from end to 




Fiff. 



91. 



end, notwithstanding that the two ends are completely 
severed where the slots G, I, come, because the 
spacing and direction of the cross-hatching are equal 
on each side of the slots, which they would not be if 
they were separate pieces. 




Fig. 92. 

Section shading or cross-hatching may sometimes 
cause the lines of the drawing to appear crooked to 
the eye. Thus, in Figure 92, the key edge on the 
appears curved inwards, while on the left 



ricrht 



SHADOW LIXES AND LINE SHADING. 



8l 



the key edge appears curved outwards, although such 
is not actually the case. The same effect is produced 




Fig- 93- 
in Figure 93 on the right-hand edge of the key, but 



not on the left-hand edge. 




Fig. 94. 

A remarkable instance of this kind is shown in 
Figure 94, when the vertical lines appear to the eye 
to be at a considerable angle one to the other, although 
they are parallel. 

The lines in sectional shadinor or cross-hatchincr 
may be made to denote the material of which the 

6 



S2 



MECHANICAL DRAWING SELF-TAUGHT. 



piece Is to be composed. Thus Professor Unwin has 
proposed die system shown in the Figures 95 and 96. 
This may be of service in some cases, but it would 



Lead 







Wood. 
Fig. or 



Steel. 



involve very much more labor than it is w^orth in 
ordinary machine shop drawings, except in the case 
of cast iron and w^ood, these two being shown in the 




Brass. Wrought Iron. Cast Iron. 

Fig. 96. 

simplest and the usual manner. It is much better to 
write the name of the material beneath the piece in a 
detail drawing. 

LINE SHADING. 

Mechanical drawings are made to look better and 
to show more distinctly by being line shaded or 
shaded by lines. The simplest form of line shading 
is by the use of the shade or shadow line. 

In a mechanical drawing the light is supposed, for 
the purposes of line shading or of coloring, to come 
in from the upper left-hand corner of the drawing 
paper; hence it falls directly upon the upper and left- 
hand lines of each piece, which are therefore rcpre- 



SHADOW LINES AND LINE SHADING. 



S3 



sented by fine lines, while the right hand and lower 
edges of the piece being on the shadow side may 
therefore, with propriety, be represented by broader 
lines, which are called shadow or shade lines. These 
lines will often serve to indicate the shape of some 





Fig. 97. 

part of the piece represented, as will be seen from the 
following examples. In Figure 97 is a piece that 
contains a hole, the fact being shown by the circle 




Fig. 99. 

being thickened at A. If the circle were thickened on 

the other side as at B, in Figure 98, it would show 

that it represented a cylindrical stem instead of a hole, 

In Figure 99 is represented a -^vasher, the surfaceii 



84 



MECHANICAL DRAWING SELF-TAUGHT. 



that are in the shadow side being shown in a shade 
Hne or shadow line, as it is often called. 

In Figure lOO is a key drawn with a shade line, 



A 




Fi 



J 



g. lOO. 




Fig. 



102. 



while in Figure loi the shade line is shown applied 
to a nut. The shade line may be produced in straight 
lines by drawing the line twice over, and slightly in- 
clining the pen, or by opening the pen points a little. 
For circles, however, it may be produced either by 
slightly moving the centre from which the circle is 
drawn, or by going over the shade part twice, and 
slightly pressing the instrument as it moves, so as to 
gradually spring the legs farther apart, the latter plan 
being generally preferable. ^ 

Figure 102 shows a German pen, that can be regu- 
lated to draw lines of various breadths. The head of 
the adjusting screw is made rather larger than usual, 
and is divided at the under side into twenty divisional 
notches, each alternate notch being marked by a figure 



SHADOW LINES AND LINE SHADING. 



S5 



on the face. By this arrangement a uniform thickness 
of line may be maintained after filling or clearing the 
pen, and any desired thickness may be repeated, with- 
out any loss of time in trial of thickness on the paper. 
A small spring automatically holds the divided screw- 
head in any place. With very little practice the click 
of the spring in the notches becomes a sufficient guide 
for adjustment, without reference to the figures on the 
screw-head. Another meritorious feature of this pen 
is that it is armed with sapphire points, which retain 
their sharpness very long, and thus save the time and 
labor required to keep ordinarv instruments in order 
for the performance of fine work. 

An example of line shading is shown in Figure 103, 
a, b and c being ports which may be shaded deeply 
or left white. 




Shading by means of lines may be used with excel- 
lent effect in mechanical drawing, not only to distin- 
guish round from flat surfaces, but also to denote to 
the eye the relative distances of surfaces. Figure 104 



86 



MECHAXICAL DRAWING SELF-TAUGHT. 



represents a cylindrical pin line shaded. As the Hght 
is supposed to come in from the upper left-hand corner, 
it will evidently fall more upon the left-hand half of 








Fig. 104. 



Fig. 105. 



the stem, and of the collar or bead, hence those parts 
are shaded with liorhter or finer lines than the rieht. 
hand sides are. 

Two cylindrical pieces that join each other may be 
line shaded at whatever angle they may join. Figure 
105 represents two such pieces, one at a right angle 
to the other, both being of equal diameter. 

Figure 106 represents a drawino- of a lathe centre 




shaded by lines, the lines on the taper parts meeting 
those on the parallel part A. and becoming more 
nearly parallel to the axis of the piece as the centre 
of the piece is approached. The same is the case 
where a piece having a curved oudine is drawn, which 
is shown in Figure 107, where the set of the bow-peo 



SHADOW LIXES AXD LIXE SHADIXG. 



87 



is gradually increased for drawing the shade lines of 
the curves. The centres of the shade curves fall in 
each case upon a line at a right angle to the axis of 




the piece, as upon the lines A, B, C, the dotted lines 
showing the radius for each curve. ^ 

The lines are made finer by closing the pen points 
by means of the screw^ provided for that purpose. 
The pen requires for this purpose to be cleaned of 
the ink that Is apt to dry in it. 

In Figure 108 line shading is shown applied to a 
ball or sphere, while in Figure 109 it is shown ap- 
plied to a pin in a socket which is shown in section. 
By showing the hollow In connection with the round 
piece, the difference between the two is quite clearly 



ss 



ME CHA NIC A L DRA WING SEL F- TA UGIIT. 



seen, the light faUing most upon the upper half 
of the pin and the lower half of the hole; This 




Fig. io8. 

perhaps is more clearly shown in the piece of 
tube in Figure no, where the thickness of the tube 
showing is a great aid to the eye. So, likewise, the 




Fig. 109. 

hollow or hole is more clearly seen where the piece is 

shown in section, as in Figure in, which is the case 

even though the piece be taper as in the figure. If 

the body be bell-mouthed, as 

in Figure 112, the hollow 

curve is readily shown by 

the shading; but to line shade 

a hollow curve without any 

of these aids to the eye, as ^^S- ^^o- 

say, to show a half of a tin tube, is a very difficult 




SHADOW LINES AND LINE SHADING. 



89 




Fij 



III. 



matter if the piece is to look natural; and all that 

be done is to shade the top 

darkly and let the light fall 

mostly at and near the bottom. 

An example of line shading to 

denote the relative distances 

from the eye of various surfaces 

is given in Figure 113, where 

the surfaces most distant are the p. ^^^ 

most shaded. The flat surfaces 

are lined with lines of equal breadth, the degrees 



can 




of 





% 


1 


T 


i! 


1 ■ :. 
1' ■ 

'1! 
'ijij 


liii' 


U 


1 


r-^^^ 



Fig. 113. 

shading being governed by the width apart of the 
lines. 



90 



MECHAXICAL DRAWING SELF-TAUGHT. 



Line shading Is often used to denote that the piece 
represented is to be of wood, the shade Hnes being In 




Fig. 114. 

some cases regular In combination with regular ones, 
or entirely irregular, as In Figure 114. 



,A. 



CHAPTER V 



MARKING DIMENSIONS. 



The dimensions of mechanical drawings are best 
marked in red ink so that they will show plainly, and 
that the lines denoting the points at which the dimen- 
sion is eiven shall not be confounded with the lines 
of the drawing. 

The dimension figures should be as large as the 
drawing will conveniently admit ; and should be marked 
at every point at which a shoulder or change of form 
or dimension occurs, except in the case of straight 
tapers which have their dimensions marked at each 
end of the taper. 

In the case of a single piece ^^// 

standing by itself the dimension 
figures may be marked all stand- 
ing one way, so as to be read 
without changing the position of 
the operator or requiring to turn 
the drawing around. This is 
done in Figure 115, which repre- 
sents the drawing of a key. The 
figures are here placed outside 
the drawing in all cases where it 
can be done, which, in the case 
of a small drawing, leaves the 
same clearer. 



-^— 






J 



Fig. 115. 
(91) 



92 



MECHANICAL DRAWING SELF-TAUGHT. 



In F'igure ii6 the dimensions are marked, running 
parallel to the dimension for which they are given, so 



^.^ 



J T 
"^ I 



Fis. ii6. 



that all measures of length stand lengthwise, and those 
of breadth across the drawing. 

Figure 117 represents a key with a sharp-cornered 
step in It. Here the two dimensions forming the 









-^-I 






^T 




^- i 


r 
4 




^ T 
4 


^t 1 




'' 












^J^:Z-. 




-WZ-. 






1 







Fig. 117. 

steps cannot bodi be coincident with It; hence they 
are marked as near to it as convenient, it beino^ un- 
derstood that they apply to the step, and not to one 
side of it. When the step has a round instead of a 
sharp corner, the radius of the arc of the corner may 
be marked, as shown in Figure 118. 

Figure 119 represents a key drawn in perspective, 



MARKING DIMENSIONS. 



93 



SO that all the dimensions may be marked on one 
view. Perspective sketches may be used for single 
pieces, as they denote the shape of the piece more 









I ¥~i 








e4.i'-r- 




35 


»^ 


^;i;' 


;s^ 




I ii 



^—l\k- 



Fig. ii8. 

clearly to the eye. On account of the skill required 
in their production, they are not, however, used in 
mechanical drawing, except as in the case of Patent- 




t\g. 119. 

Office or similar drawings, where the form and con- 
struction rather than the dimension is the information 
sought to be conveyed. 



CHAPTER VL 
IHE ARRANGEMENT OF DIFFERENT VIEWS. 

THE DIFFERENT VIEWS OF A MECHANICAL DRAWING, 

The word elevation, as applied to mechanical draw- 
ing, means simply a view; hence a side elevation is a 
side view, or an end elevation is an end view. 

The word plan is employed in place of the word 
top ; hence a plan view is a top view, or a view look- 
ing down upon the top of the piece. 

A general view means a view showing the machine 
put together or assembled, while a detail drawing is 
one containing a detail, as a part of the machine or a 
single piece disconnected from the other parts of the 
whole machine. 

It is obviously desirable in a mechanical drawing to 
present the piece of work in as few views as possible, 
but in all cases there must be a sufficient number to 
permit of the dimensions in every necessary direction 
to be marked on the drawing. Suppose, then, that 
in Figure 120 we have to represent a solid cylinder, 
whose length equals its diameter, and it is obvious 
that both the diameter and length may be marked in the 
•one view given ; hence, a second view, such as shown 
by the circle in Figure 121, is unnecessary, except it 
be to distinguish the body from a cube, in which the 

(94) 



THE ARRANGEMENT OF DIFFERENT VIEWS. 



95 



one view would also be sufficient whereon to mark all 
the dimensions necessary to enable the piece to be 
made. It happens, however, that a cube and a cylln- 




Fiof. T20. 



Fii 



121. 



der are the only two figures upon which all the di- 
mensions can be marked on one view of the piece, 
and as cylindrical pieces are much more common in 
machine work than cubes are, it is taken for granted 
that, where the pieces are cylindrical, but one view shall 
be used, and that where they are cubes either two 
views shall be given, or where they are square a cross 
shall be marked upon the parts that are square ; 
thus, in Figure 122, Is shown a cross formed by the 
lines A B across the face of the drawing, which saves 
making- a second view. 





Fig. 122. 

It would appear that under some conditions this 
might lead to error; as, for example, take the piece in 
Figure 123, and there is nothing to denote which is 



g5 MECHANICAL DRAWING SELF-TAUGHT. 

the length and which is the diameter of the piece, but 
there is a certain amount of custom in such cases that 
will usually determine this point; thus, the piece will 
be eiven a name, as pin or disk, the one denoting that 
its diameter is less than its length, and the other that 
its diameter is crreater than its lenorth. In the absence 
of any such name, it would be in practice assumed 
that it was a pin and not a disk; because, if it were a 
disk, it would either be named or shaded, or a second 
view given to show its unusual form, the disk being a 
more unusual form than the pin-form in mechanical 
structures. As an example of the use of the cross to 




o 








a 




■J 




X 






^^^ 






Fig. 124. 



Fig. 125. 



denote a square, we have Figure 1 24, which repre- 
sents a piece having a hexagon head, section a, a\ 
that is rectangular, a collar b, a square part c, and a 
round stem d. Here it will be noted that it is the 
rectangular part a, a\ that renders necessary two views, 
and that in the absence of the cross, yet another view 
would be necessary to show that part c is square. 
A rectangular piece always requires two views and 



THE ARRANGEMENT OF DIFFERENT VIEWS. 



97 



sometimes three. In Figure 125, for example, is a 
piece that would require a side view to show the 





Fig, 126. Fig. 127. 

length and breadth, and an edge view to show the 
thickness. Suppose the piece to be wedge-shaped in 
any direction ; then another view will be necessary, a-s 
is shown in Figs. 126 and 127. In the former the 




Far. 128. 



wedge or taper is in the direction of its length, while 
in the latter it is in the direcdon of its thickness. 
Outline views, however, will not in some cases show 
the form of the figure, however many views be 



gg MECHANICAL DRAWING SELF-TAUGHT. 

presented. An example of this is given in Figure 
128, which represents a ring having a hexagon cross 
section. A sectional edge view is here necessary in 






Fig. 129. 

order to show the hexagonal form. Another example 
of this kind, which occurs more frequently in practice, 
is a cupped ring such as shown in Figure 129. 

EXAMPLES. 

Let it be required to draw a rectangular piece such 
as is shown in two views in Figure 130, and the pro- 
cess for the pencil lines is as follows: 



iSidcVic'o 



End 
View 



Fig. 130. 



With the bow-pencil set to half the required length 
and breadth of the square the arcs i, 2, 3 and 4, in 
Figure 131, are marked, and then the lines 5 and 6, 



THE ARRANGEMENT OF DIFFERENT VIEWS. 



99 



letting them run past the width of the arcs 3 and 4. 
There is no need to pencil in lines 7 and 8, since they 
can be inked in without pencilling, because it is 
known that they must meet the arcs 3 and 4 and ter- 




Fig. 131. 

minate at the lines 5 and 6. The top and bottom 
lines of the edge view are merely prolongations of 
lines 5 and 6; hence the lines 9 and 10 are drawn the 
requisite distance apart for the thickness and to meet 
the top and bottom lines. The lines are then inked 
in, the pencil lines rubbed out, and the drawing will 
appear as in Figure 130. 






^nd View 



Fig. 



Side View 
132. 



Suppose, however, that the piece has a step in it, as 
in Figure 132, and the pencilling will be as in Figure 
133. From the centre, the arcs i, 2, 3 and 4 for the 
outer, and arcs 5, 6, 7 and 8 for the inner square are 
marked; lines 9 and 10, and their prolongations, 11 



lOO 



MECHANICAL DRAWING SELF-TAUGHT. 



and 1 2, for the edge view, are then pencilled ; lines 
13 and 14, and their prolongations, 15 and 16, are then 
pencilled, and dots to show the locations for lines 21 
and 22 maybe marked and the penciUing is complete. 



11 



17 



13 



18 



14 



15 



21 



22 



20 



16 



23 



10 



12 



Fig. 133- 

Lines 17, 18, 19, 20, 21, 22, and 23 may then be 
inked in, in the order named, and then lines 9, 10, 
II, 12, 13, 14, 15 and 16, when the inking in will be 
complete. 

In inking in horizontal lines begin at the top and 
mark in each line as the square comes to it; and in 
inking the vertical ones begin always at the left hand 
line and mark the lines as they are come to, moving 
the square or the triangle to the right, and great 
care should be taken not to let the lines cross where 
they meet, as at the corners, since this would greatly 
impair the appearance of the drawing. 

These ficrures have been drawn without the aid of 
a centre line, because from, their shapes it was easy 
to dispense with it, but in most cases a centre line is 
necessary; thus in Figure 134 we have a body having a 
number of steps. The diameters of these steps are 
marked by arcs, as in the previous examples, and 
their lengths may be marked by applying the measur- 
ing rule direct to the drawing paper and making the 
necessary pencil mark. 



i 



THE ARRANGEMENT OF DIFFERENT VIEWS. 



lOI 



But it would be tedious to mark the successive 
steps true one with the other by measuring each step, 
because one step would require to be pencilled in 
before the next could be marked. To avoid this the 
centre line i, Figure 134, is first marked, and the arcs 



&ide View End View 

Fig. 134. 

for the steps are then marked as shown. Centre lines 
are also necessary to show the alignment of one part 
to another; thus in Figure 135 is a cube with a hole 



Fig. 135- 

passing through it. The dotted lines in the side view 
show that the hole passes clear through the piece 
and is a parallel one, while the centre line, being cen- 
tral to the oudine throughout the piece, shows that 
the hole Is equidistant, all through, from the walls of 
the piece. 

The pencil lines for this piece would be marked as 
in Figure 136, line i representing the centre line from 
which all the arcs are marked. It will be noted that 



102 



MECHANICAL DRAWING SELF-TAUGHT. 



the length of the piece is marked by arcs which occur, 
because being a cube the set of the compasses for 
arcs 2, 3, 4 and 5 will answer without altering to 
mark arcs 6 and 7. 



- 5 ~ ! 








6 ,- 


1 




, 





End View 



Side View 



Fig. 136. 



If the hole in the piece w^ere a taper or conical one, 
it would be denoted by the dotted lines, as in Figure 
137, and that the taper is central to the body is shown 




_ .....J 



Fig. 137. 

by these dotted lines being equidistant from the cen- 
tre line. 

Suppose one of the sides to be tapered, as is the 
side A, in Figure 138, and that the hole is not central, 
and both facts will be shown by the centre lines i 
and 2 in the figure. The measurement of face A 
would be marked from A to line B at each end, but 
the distance the hole was out of the centre would be 



THE ARRANGEMENT OF DIFFERENT VIEWS. 103 

marked by the distance between the centre line 2 
and the edge C of the piece. 



•( 








— — « 




2 


^ 




1 




^ 


1 



















Fig. 138. 

If the hole did not pass entirely through the piece, 
the dotted lines would show it, as in Figure 139. 




Fii 



'^- 139- 

The designations of the views of a piece of work 
depend upon the position in which the piece stands, 




mo 




Fig. 140. 



04 



MECHANICAL DRAWING SELF-TAUGHT. 



when in place upon the machine of which it formj 
a part. Thus in Fio-ure 140 is a lever, and if its shaft 
stood horizontal when the piece is in place in the 




Fig. 141. 

machine, the view given is an end one, but suppose 
that the shaft stood vertical, and the same view be- 
comes a plan or top view. 



N 



S 



D 

"1 — c 



^ S 



Fig. 142. 



THE ARRANGEMENT OF DIFFERENT VIEWS. 



05 



In Figure 142 is a view of a lever which is a side 
view if the lever stands horizontal, and lever B hangs 
down, or a plan view if the shaft stands horizontal, 
but lever B stands also horizontal. We may take the 
same drawing and turn it around on the paper as in 
Figure 143, and it becomes a side view if the shaft 
stands vertical, and a plan view if the shaft stands hori- 
zontal and arm D vertical above it. 

In a side or an end view, the piece that projects 
highest in the drawing is highest when upon the 



JL 



Fi? 



143- 



machine ; also in a side elevation the piece that Is at 
the highest point in the drawing extends farthest 
upward when the piece is on the machine. But in 
a plan or top view the height of vertical pieces is 
not shown, as appears in the case of arm D in Figure 

143- 

In either of the levers, Figures 142 or 143, all the 
dimensions could be marked if an additional view 
were given, but this will not be the case if an eye 



io6 



MECHANICAL DRAWING SELF-TAUGHT, 



have a slot in it, as at E, in Figure 144, or a jaw have 
a tongue in it, as at F : hence, end views of the eye 
and the jaw must be given, which ma}^ be most con- 
veniently done by showing them projected from the 
ends of those parts as in the figure. 

This naturally brings us to a consideration as to 
the best method of projecting one view from another. 



encf view of £ 




Fig. 144. 

As a oreneral rule, the side elevation or side view is 
the most important, because it shows more of the 
parts and details of the work ; hence it should be 
drawn first, because it affords more assistance in 
drawing the other views. 

There are two systems of placing the different views 



THE ARRANGEMENT OF DIFFERENT VIEWS. iqj 

of a piece. In the first the views are presented as the 
piece would present itself if it were laid upon the paper 
for the side view, and then turned or rolled upon the 
paper for the other views, as shown in Figure 145, 
in which the piece consists of five sections or mem- 
bers, marked respectively A, B, C, D, and E. Now if 
the piece were turned or rolled so that the end face 



D 

D 
D 




A 


c 
c 








B 






1 A 






1 


E 


! 


1 


B 


j 
c 










Fig 


A 


^5- 





of B were uppermost, and the member E was beneath, 
it will, by the operation of turning it, have assumed 
the position in the lower view marked position 2 ; 
while if it were turned over upon the paper in the 
opposite direction it would assume the position 
marked 3. This gives to the mind a clear idea of 



loS 



MECHANICAL DRAWING SELF-TAUGHT. 



the various views and positions; but it possesses some 
disadvantages: thus, if position i is a side elevation or 
view of the piece, as it stands when in place of the 
machine, then E is naturally the bottom member; but 
it is shown in the top view of the drawing, hence what 
is actually the bottom view of the piece (position 3) 
becomes the top view in the drawing. A second dis- 
advantage is that if we desire to put in dotted lines, 




Fig. 146. 

to show how one view is derived from the other, and 
denote corresponding parts, then these dotted lines 
must be drawn across the face of the drawino- makin^r 
it less distinct; thus the dotted lines connecting stem 
E in position i to E in position 3, pass across the faces 
of both A and B of position i. 

In a large drawing, or one composed of many mem- 
bers or parts, it would, therefore, be out of the ques- 



THE ARRANGEMENT OF DIFFERENT VIEWS. 109 

t'lon to mark in the dotted lines. A further disadvan- 
tage in a large drawing is that it is necessary to go 
from one side of the drawino- to the other to see the 
construction of the same part. 

To obviate these difficulties, a modern method is to 
suppose the piece, instead of rolling upon the paper, 
to be lifted from it, turned around to present the re- 




A 



Fig. 147. 
quired view, and then moved upwards on the paper 
for a top view, sideways for a side view, and below 
for a bottom view. Thus the three views of the piece 
in Figure 145 would be as in Figure 146, where posi- 
tion 2 is obtained by supposing the piece to be lifted 
from position i, the bottom face turned uppermost, 
and the piece moved down the paper to position 2, 



jjQ MECHANICAL DRAWING SELF-TAUGHT. 

which is a bottom view of the piece, and the bottom 
view in the drawing. Similarly, if the piece be lifted 
from position i, and the top face in that figure is 
turned uppermost, and the piece is then slid upwards 
on the paper, view 3 is obtained, being a top view of 
the piece as it lies in position i, and the top view in 
the drawing. Now suppose we require to find the 




Fig. 148. 

shape of member B, then in Figure 145 we require to 
look at the top of position i, and then down below to 
position 2. 

But in Figure 146 we have the side view and end 
view both together, while the dotted lines do not re- 
quire to cross the face of the side view. Now sup- 



THE ARRANGEMENT OF DIFFERENT VIEWS. m 

pose we take a similar piece, and suppose its end 
faces, as F, G, to have holes in them, which require to 
be shown in both views, and under the one system the 
drawing would, if the dotted lines were drawn across, 
appear as in Figure 147, whereas under the other 
system the drawing would appear as in Figure 148. 
And it follows that in cases where it is necessary to 
draw dotted lines from one view to the other, it is 
best to adopt the new system. 



CHAPTER VIL 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. 

Let it be required to draw a machine screw, and it 
is not necessary, and therefore not usual in small 
screws to draw the full outline of the thread, but to 
represent it by thick and thin lines running diagonally 
across the bolt, as in Figure 149, the thick ones repre- 



A 1 



\ 




Fig. 149. 



Fig. 



IsO. 



Fig. I5I' 



senting the bottom, and the thin ones the top of the 
thread. The pencil lines would be drawn in the order 
shown in Figure 150. Line i is the centre line, and 
line 2 a line to represent the lower side of the head ; 
from the intersection of these two lines as a centre (as 
at A) short arcs 3 and 6, showing the diameter of the 
thread, are marked, and the arcs 5 and 6, representing 
the depth of the thread, are marked. The arc 7, rep- 
resenting the head, is then marked. The vertical 
lines 8, 9, 10, and 11 are then marked, and the out- 
line of the screw is complete. The thick lines repre- 
(112) 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. 113 

senting the bottom of the thread are next marked in, 
as in Figure 151, extending from hne 9 to line 10. 
Midway between these Hnes fine ones are made for 
the tops of the thread. All the lines being pencilled 
in, they may be inked in with the drawing instruments, 
taking care that they do not overrun one another. 
When the pencil lines are rubbed out, the sketch will 
appear as in Figure 149. 

For a bolt with a hexaofon head the lines would be 
drawn in the order shown in Figure 152. At a right- 




Fig. 152. 

angle to centre line i, line two is drawn. The pencil- 
compasses are then set to half the diameter of the 
bolt, and from point A arcs 3 and\are pencilled, thus 
showing the width of the front flat of the head, as well 
as the diameter of the stem. From the point where 
these arcs meet line 2, and with the same radius, arcs 
5 and 6 are marked, showing the widths of the other 



MECHANICAL DRAWING SELF-TAUGHT. 



114 

two flats of the head 



The thickness of the head and 
the length of the bolt head may then be marked either 
by placing a rule on line i and marking the short lines 
(such as line 7) a cross line i, or the pencil-compasses 
may be set to the rule and the lengths marked from 




Fig. 153- 
point A. In the United States standard for bolt heads 
and nuts the thickness of the head is made equal to 
the diameter of the bolt. With the compasses set for 
the arcs 3 and 4, we may in two steps, from A along 
the centre line, mark off the thickness of the head 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. 115 

without iisinof the rule. But as the rule has to be 
applied along line i to mark line 7 for the length of 
the bolt, it is just as easy to mark the head thickness 
at the same time. The line 8 showing the length of 
the thread may be marked at the same time as the 
other lengths are marked, and the outlines 9, 10, 11, 
12,13 may be drawn in the order named. We have 
now to mark the arcs at the top of the flats of the 
head to show the chamfer, and to explain how these 
arcs are obtained we have in Figure 153 an enlarged 
view of the head. It is evident that the smallest 
diameter of the chamfer is represented by the circle A, 
and therefore the length of the line B must equal A. 
It is also evident that the outer edge of the chamfer will 
meet the corners at an equal depth (from the face of the 
nut) , as represented by the line C C, and it is obvious that 
the curves that represent the outline of the chamfer 
on each side of the head or nut will approach the face 
of the head or nut at an equal distance, as denoted 
by the line D D. It follows that the curve must in 
each case be such as will, at each of its ends, meet the 
line C, and at its centre meet the line D D, the centres 
of the respective curves being marked in the figure 
byX. 

It is sufficiently accurate, therefore, for all practical 
purposes to set the pencil on the centre-line at the 
point A in Figure 152 and mark the curve 14, and to 
them set the compasses by trial to mark the other 
two curves of the chamfer, so that they shall be an 
equal distance with arc 14 from line 9, and join lines 
10 and 13 at the same distance from line 9 that 14 joins 
lines 3 and 4, so that as in Figure 153 all three of 



ii6 



MECHANICAL DRAWING SELF-TAUGHT. 



the arcs would touch a Hne as C, and another line 
as D. 

The United States standard sizes for forged or un- 




1^-^ \ 

Fig. 154- 

finished bolts and nuts are mven in the followino- table, 
Figure 154 showing the dimensions referred to in the 
table. 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. ny 
UNITED STATES STANDARD DIMENSIONS OF BOLTS AND NUTS. 



Bolt- 


Bolt Head and Nut. 




Diameter. 


P ^ 


Long diameter, /, 

or diameter across 

corners. 


HI 


1 









Hr* 


!ZJ 


. ■ 


^p. 






•^ p p 


?" 





o 


H 


to "^ 






p 3 a 


_ 


•^ 


3. 




If 


n 


m 

^ 

c 






g 






• O 


X 

o 

3 


P 


t« c "^ 

:^ 3- 

• " ro 

• X 
■I 1 


c 

il5 



p 


i 


.185 


20 


A 


M 


^ 


i 


i 


fV 


.240 


18 


ii 


M 


19 
32 


5 


M 


1 


.294 


16 


2 5 

3 2 


M 


\\ 


f 


M 


7 


.345 


14 


§1 


l.\ 


M 


tV 


M 


^ 


.400 


13 


1 


U 


1 


1 


T^ 


T% 


.454 


12 


1^ 


11 


fi 


t\ 


M 


1 


.507 


11 


1/2 


u 


ItV 


1 


H 


f 


.620 


10 


I/tt 


If 


U 


3. 

4 




1 


.731 


9 


Iqi 


2.V 


ItV 


1 


M 


1 


.837 


8 


1^" 


2t% 


If 


\ 


if 


li 


.940 


7 


2.\ 


2A 


lit 


u 


If 


u 


1.065 


7 


2A 


2M 


2 


u 


1 


If 


1.160 


6 


2M 


3#2 


2A 


If 


lA 


u 


1.284 


6 


21 


3M 


21 


u 


ly'^ 


11 


1.389 


5* 


m 


3t 


2A 


11 


1ft 


If 


1.491 


5 


3A 


31 


21 


If 


11 


ll 


1.616 


5 


3p 


4/^ 


2if 


1 7 

■•■8 


IM 


2 


1.712 


4-1 


3M 


4M 


3i 


2 


ly^^ 


2i 


1.962 


4i 


4^V 


4if 


3^ 


2i 


If 


2i 


2.176 


4 


^^ 


5M 


3| 


2i 


IM 


21 


2.426 


4 


4p 


6 


4i 


2f 


2i 


3 


2.629 


31 


5M 


6M 


41 


3 


2t% 


3i 


2.879 


3^ 


5M 


7tV 


5 


3i 


21 


3J 


3.100 


3i 


63V 


m 


51 


31 


2|^ 


^ 31 


3.317 


3 


61 


8i 


5f 


3f 


2i 




3.567 


3 


7tV 


814 


6i 


4 


3A 


'"4r" 


3.798 


2| 


• 16 
7i 


'-'s 2 


61 


4i 


sf 


4^ 


4.028 


21 


Vif 


9«f 


6| 


41 


3tV 


41 


4.256 


21 


8-1 


lOi 


7i 


41 


31 


5 


4.480 


2.V 


8|f 


1011 


71 


5 


3H 


5} 


4.730 


2J 


9} 


llA 


8 


5i 


4 


5^ 


4.953 


2f 


9|J 


1114 


81 


51 


4t\ 


5f 


5.203 


2| 


Vh\ 


12i 


8f 


5f 


41 


6 


5.423 


2i 


mi 


12ff 


9i 


6 


4A 



Diameter at the root of the thread. 



ii8 



MECHANICAL DRAWING SELF-TAUGHT, 



The basis of the Franklin Institute or United States 
standard for the heads of bolts and for nuts is as fol- 
lows : 

The short diameter or width across the flats is equal 
to one and one-half times the diameter plus \ inch 
for rough or unfinished bolts and nuts, and one and 
one-half times the bolt diameter plus /g inch for fin- 
ished heads and nuts. The thickness is, for rough 
heads and nuts, equal to the diameter of the bolt, 
and for finished heads and nuts /g inch less. 



I 





Fii 



155. 



Fig. 156. 



The hexagonal or hexagon (as they are termed In 
the shop) heads of bolts may be presented in two 
w^ays, as is shown In Figures 155 and 156. 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. ng 

The latter is preferable, inasmuch as it shows the 
width across the fiats, which is the dimension that is 
worked to, because it is where the wrench fits, and 
therefore of most importance; whereas the latter gives 
the length of a flat, which is not worked to, except 
incidentally, as it were. There is the objection to the 
view of the head, given in Figure 156, however, that 
unless it is accompanied by an end view it somewhat 
resembles a similar view of a square head for a bolt. 
It may be distinguished therefrom, however, in the 
following points: 

If the amount of chamfer is such as to leave the 
chamfer circle (as circle A, in Figure 153) of smaller 
diameter than the width across the flats of the bolt- 
head, the outline of the sides of the head will pass 
above the arcs at the top of the flats, and there will 
be two small flat places, as A and B, in Figure 156 
(representing the angle of the chamfer), which will 
not meet the arcs at the top of the flats, but will join 
the sides above those arcs, as in the figure; which is 
also the case in a similar view of a square-headed 
bolt. It may be distinguished therefrom, however, 
in the following points : 

If the amount of chamfer is such as to leave the 
chamfer circle (A, Figure 153) of smaller diameter 
than the width across the flats of the bolt-head, the 
outline of the sides will pass above the arc on the 
flats, as is shown in Figure 157, in which the chamfer 
A meets the side of the head at B, and does not, 
therefore, meet the arc C. The length of side lying 
between B and D in the side view corresponds with 
the part lying between E and F in the end view. 



I20 



MECHANICAL DRAWING SELF-TAUGHT. 



If we compare this head with similar views of a 
square head G, both being of equal widths, and having 
their chamfer circles at an equal distance from the 
sides of the flats, and at the same angle, we perceive 
at once that the amount of chamfer necessary to give 




the same distance between the chamfer circle and the 
side of the bolt (that is, the distance from J to K, 
being equal to that from L to M), the length of the 
chamfer N for the square head so gready exceeds the 
length A for the hexagon head that the eye detects 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. 12 1 



drawn, but just 
the case of the 
Figure 157, the 



the difference at once, and is instinctively informed 
that G must be square, independently of the fact 
that in the case of the square head, N meets the arc 
O, while in the hexagon head. A, which corresponds 
to N, does not meet the arc C, which corresponds 
to O. 

When, however, the chamfer is 
sufficient to meet the flats, as in 
hexagon H, and the square I, in 
chamfer line passes from the chamfer circle to the 
side of the head, and the distinction is greater, as will 
be seen by comparing head H with head I, both being 
of equal width, having the same angle of chamfer, and 
an amount just sufficient to meet the sides of the flats. 
Here it will be seen that in the hexagon H, each side 
of the head, as P, meets the chamfer circle A. 
Whereas, in the square head these two lines are 
joined by the chamfer line Q, the figures being quite 
dissimilar. 




Side 



Fig. 158. 



It is obvious that whatever the degree or angle of 
the chamfer may be, the diameter of the chamfer 



I 22 



MECHANICAL DRAWING SELF-TAUGHT. 



circle wDl be the same in any view in which the head 
may be presented. Thus, in Figure 158, the Hne G 
in the side view is in length equal to the diameter of 
circle G, in the end view, and so long as the angle 
of the chamfer is forty-five degrees, as in all the views 
hitherto given, the width of the chamfer will be equal 
at corresponding, points in the different views ; thus 
in the figure the widths A and B in the two views 
are equal. 

If the other view^ showing a corner of the head in 
front of the head be given, the same fact holds good, 
as is shown in Figure 159. That the two outside fiats 




/^^^^^^ — -\ 



Fig. 159- 



should appear in the drawing to be half the width of the 
middle flat is also shown in Figure 158, where D and 
E are each half the width of C. Let us now suppose, 
that the chamfer be given some other angle than that 
of 45 degrees, and we shall find that the effect is to 
alter the curves of the chamfer arcs on the flats, as is 
shown in Figure 160, where these arcs E, C, D are 
shown less curved, because the chamfer B has more 
anMe to the flats. As a result, the width or distance 
between the arcs and line G is different in the 
two views. On this account it is better to draw the 
chamfer at 45 degrees, as correct results may be ob- 
tained with the least trouble. 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. 123 

If no chamfer at all is to be given, a hexagon 
head may still be distinguished from a square one, 
providing that the view giving three sides of the head. 



G- 



£ T C T n 



Side 




JSiid 



Fig. 160. 



as in Figure 158, is shown, because the two sides D 
and E being half the width of the middle one C, imparts 
the information that it is a hexagon head. If, how- 
ever, the view showing but two of the sides and a 
corner in front is given, and no chamfer is used, it 
could not be known whether the head was to be hex- 
agon or square, unless an end view be given, as in 
Figure 161. 

If the view showing a full side of the head of a 
square-headed bolt is given, then either an end view 
must be given, as in Figure 162, or else a single view 
with a cross on its head, as in Figure 163, may be 
given. 

It is the better plan, both In square and hexagon 
heads, to give the view in which the full face of a fiat 
is presented, that is, as in Figures 155 and 163; be- 
cause, in the case of the square, the length of a side 
and the width across the head are both given in that 
view ; whereas if two sides are shown, as in Figure 
161, the width across flats is not given, and this is the 



124 



MECHAXICAL DRAWING SELF-TAUGHT. 



dimension that is wanted to work to, and not the 






Fic;. i6i. 





o 


1 

1 





















Fig. 162. 




Fig. 163. 
width across corners. In the case of a hexaeon the 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. 125 

middle of the three flats is equal in width to the di- 
ameter of the bolt, and .the other two are one-half its 
width ; all three, therefore, being marked with the same 
set of compasses as gives the diameter of the body of 
the bolt, were as shown in Figure 152. For the width 
across fiats there is an accepted standard; hence 
there is no need to mark it upon the drawing, unless 
in cases where the standard is to be departed from, 



8d 



Fig. 164. 



in which event an end view may be added, or the 
view showing two sides may be given. 

To draw a square-headed bolt, the pencil lines are 
marked in the order shown by figures in Figure 164. 
The inking in is done in the order of the letters a, b, c, 
etc. It will be observed that pencil lines 2, 9, and 10 
are not drawn to cross, but only to meet the lines at 
their ends, a point that, as before stated, should always 
be carefully attended to. 




Fig. 165. 

To draw the end view of a hexaoron head, first draw 
a circle of the diameter across the flats, and then rest 



126 



MECHANICAL DRAWING SELF-TAUGHT. 



the triangle of 60 degrees on the blade soi the square, 
as at T I, in Figure 165, and mark the lines a and b. 
Reverse the trianorle, as at T 2, and draw lines c and 




Fig. 166. 

d. Then place the triangle as in Figure 166, and 
draw the lines e and/] 

If the other view of the head is to be drawn, then 
first draw the lines a and b in Figure 167 with the 
square, then with the 60 degree triangle, placed on 
the square S, as at T i, draw the lines c, d, and turn- 
ing the square over, as at T2, mark lines e andy[ 




/ 



Fig. 167. 

If the diameter across corners of a square head is 
given, and it be required to draw the head, the pro- 
cess is as follows: For a view showing one corner in 
front, as in Figure 168, a circle of the given diameter 
across corners is pencilled, and the horizontal centre- 
line a is marked, and the triangle of 45 degrees is 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. 127 

rested against the square blade S, as in position T i, 
and lines b and c marked, b being marked first ; and 
the triangle is then slid along the square blade to po- 
sition T I, when line c is marked, these two lines just 




<^ 



Fig. 168. 



meetinor the horizontal line a, where it meets the cir- 
cle. The triangle is then moved to the left, and line 
d, joining the ends of b and c, is marked, and by mov- 
ing it still farther to the left to position T 2, line e is 
marked. Lines b, c, d, and e are, of course, the only 
ones inked in. 

If the flats are to lie In the other direction, the 
pencilling will be done as in Figure 169. The circle 




Fig. 169. 

IS marked as before, and with the triangle placed as 
shown at T I, line a, passing through the centre of 
the circle, is drawn. By moving the triangle to the 
right its edge B will be brought into position to mark 



Q 



128 



MECHANICAL DRAWING SELF-TAUGHT. 



line ^, also passing through the centre of the circle. 
All that remains is to join the ends of these two lines, 
using the square blade for lines c, d, and the triangle 
for e and f, its position on the square blade being 
denoted at T 3; lines c,d, e,f, are the ones inked in. 

For a hexagon head we have the processes, Figures 
170 and 171. The circle is struck, and across it line 




Fig. 170. 

a, Figure 170, passing through its centre, the triangle 
of sixty degrees will mark the sides b, c, and d, e, as 
shown, and the square blade is used ior f, g. 

The chamfer circles are left out of these figures to 
reduce the number of lines and so keep the engraving 




Fig. 171. 

clear. Figure 171 shows the method of drawing a 
hexagon head when the diameter across corners is 



EXAMPLES EV BOLTS, Xi'TS, AXD POLYGONS. 



129 



oflven, the lines being drawn in the alphabetical ordrr 
marked, and the triangle used as will now be under- 
stood. 

It may now be pointed out that the triangle may be 
used to divide circles much more quickly than they 
could be divided by stepping around them with com- 
passes. Suppose, for example, that we require to 
divide a circle into eight equal 'parts, and we may do 
so as In Figure 172, line a being marked from the 





V 



i 



Fig. 172. Fig. 173. 

square, and lines b, c and d from the triangle of forty- 
five decrees; the lines to be inked in to form an oc- 
tagon need not be pencilled, as their location is clearly 
defined, being lines joining the ends of the lines 
crossing the circle, as for example, lines e,f. 

Let it be required to draw a polygon having twelve 
equal sides, and the triangle of sixty is used, 
marking all the lines within the circle in Figure 173, 
except a, for which the square blade is used ; the only 
lines to be inked in are such as b, c. In this example 
there is a corner at the top and bottom, but suppose 
it were required that a flat should fall there instead 
of a corner; then all we have to do is to set the square 
9 



130 



MECHANICAL DRAWING SELF-TAUGHT. 



blade S at the required angle, as in Figure 174, and 
then proceed as before, bearing in mind that the point 
of the circle nearest to the square blade, straight-edge, 




Fig. 174, 

or whatever the triangle is rested on, is always a 
corner of a polygon having twelve sides. ^ 

In both of these examples we have assumed that 
the diameter across corners of the polygon was 




Fig. 175- 
given, but suppose the diameter across the flats were 
given, and the construction is a litde more complicated. 
Circle a, a, in Figure 175, is drawn of the required 
diameter across the flats, and the lines of division are 



EXAMPLES EV BOLTS, NUTS, AND POLYGONS. 131 

drawn across with the triangle of 60 as before; the 
triangle of 45 is then used to draw the four lines^ b, c, 
d, e, joining the ends of lines i, j, k, /, and touching 
the inner circle, a, a. The outer circle is then pencilled 
in, touching the lines of division where they meet the 
lines b, c, d, e, and the rest of the lines for the sides of 
the polygon may then be drawn within the outer circle, 
as at g, h. 

It is obvious, also, that the triangle may be used to 
draw slots radiating from a centre, as in Figure 176, 




\ 
Fig. 176. 

where it is desired to draw a chuck-plate having 6 
slots. The triangle of 60 is used to draw the centre 
lines, a, b, c, etc., for the slots. From, the centre, the 
arcs e, f, g, Ji, etc., are marked, showing where the 
centres will fall for describing the half circles forming 
the ends of the slots. Then half circles, i, j, k, /, etc., 
being drawn, the sides of the slots may be drawn in 
with the triangle, and the outer circle and the slots 
inked in. 

If the slots are not to radiate from the centre of 
the circle the process is as follows: 

The outer circle a, Figure i ^'], being drawn, an inner 
one b is drawn, its radius equalling the amount; the 



1^2 



MECHAXICAL DRAWIXG SELF-TAUGHT. 



J- 

centres of the slots are to point to one side of the 
centre of circle a. The triancrle is then used to 
divide the circle into the requisite number of divisions 




c for the slots, and arcs i, j, are then drawn for the 
leno-ths of the slots. The centre lines e are then 
drawn, passing through the lines c, and the arcs /, y, 
etc., and touching the perimeter of the inner circle b; 
arcs f, g, are then marked in, and their sides joined 
with the triangle adjusted by hand. All that w^ould 
be inked in black are the outer circle and the slots, but 
the inner circle b and a centre line of one of the 
slots should be marked in red ink to show how the 
inclination of the slot was obtained, and therefore its 
amount. 

For a five-sided figure it is best to step around the 
circumference of the circle with the compasses, bu? 
for a three-sided one, or trigon, the construction is as 
follows : It will be found that the compasses set to 
the radius of a circle will accurately divide it into six 
equal divisions, as is shown in Figure 178; hence 
every other one of these divisions will be the location 
for a corner of a trio^on. 



±:XAMPLES IX BOLTS, XUTS, AXD POLYGOXS, 133 

The circle being drawn, a line A, 179, Is drawn 
through Its centre, and from Its intersection with the 
circle as at b, here a step on each side is marked as c,d, 





Fig. 178, Fig. 179. 

then lines c to d, and c and d to e, where A meets, the 
circle will describe a trigon. If the figure is to stand 
vertical, all that is necessarv is to draw the line a 




vertical, as In Figure 180. A ready method of getdng 
the dimension across corners, across the flats, or the 
length of a side of a given polygon, is by means of 
diagrams, such as shown In the following figures, 
which form excellent examples for practice. X 

Draw the line O P, Figure 181, and at a right angle 
to it the line O B ; divide these two lines Into parts of 
one Inch, as shown in the cut, which is divided Into 



134 



MECHANICAL DRAWIXG SELF-TAUGHT. 



inches and quarter inches, and from these points oj 
division draw lines crossing each other as shown. 







Fig. i8i. 



From the point O, draw diagonal lines, at suitable 
angles to the line O P. As shown in the cut, these 
diagonal lines are marked : 

40 degrees for 5 sided figures. 

45 ■ " '^ 6 " 

49 " " 7 " " 

S2}4 •' " 8 " 

55>^ " " 9 " 
But still others could be added for ficrures havinor a 
greater number of sides. 

i. Now it will be found as follows : Half the diam- 



EXAMPLES IN BOLTS, .VUTS, AND POLYGONS. j-^- 

eter, or the radius of a piece of cylindrical work being 
given, and the number of sides it is to have being 
stated, the length of one side will be the distance 
measured horizontally from the line O B to the diag- 
onal line for that particular number of sides. 

Example. — A piece of work is 2}^ inches in diam- 
eter, and is required to have 9 sides : what will be the 
length of the sides or flats? 

Now the half diameter or radius of 2^ inches 
is I ^ inches. Then look along the line O B for i ^, 
which is denoted in the cut by figures and the arrow 
A ; set one point of the compasses at A, and the 
other at the point of crossing of the diagonal line with 
the I y^ horizontal line, as shown in the figure at a, 
and from A to ^ is the length of one side. 

Again : A piece of work, 4 inches in diameter, is 
to have 9 sides : how long will each side be ? 

Now half of 4 is 2, hence from B to b Is the length 
of each side. 

But suppose that from the length of each side, and 
the number of sides, it is required to find the diameter 
to which to turn the piece; that is, its diameter across 
corners, and we simply reverse the process thus : i\ 
body has 9 sides, each side measures |J: what is its 
diameter across corners ? 

Take a rule, apply it horizontally on the figure, and 
pass it along till the distance from the line O B to the 
diagonal line marked 9 sides measures |J, which is 
from I Ji|^ on O B to <2, and the i J^ is the radius, which, 
multiplied by 2, gives 2j^ inches, which is the required 
diameter across corners. 

For any other number of sides the process is just 



J. 5 MECHANICAL DRAWING SELF-TAUGHT. 

the same. Thus: A body is 3^ inches in diameter, 
and is to have 5 sides : what will be the length of each 
side ? Now half of 3^ is i ^ ; hence from i ^ on the 
line O B to the point C, where the diagonal line crosses 
the I y^ line, is the length of each of the sides. 

2. It will be found that the leno^th of a side of a 
square being given, the size of the square, measured 
across corners, will be the length of the diagonal line 
marked 45 degrees, from the point O to the figures 
indicating, on the line O B or on the line O P, the 
length of one side. 

Example. — A square body measures i inch on each 
side : what does it measure across the corners ? An- 
swer : From the point O, along diagonal line marked 
45 degrees, to the point where it crosses the lines i 
(as denoted in the figure by a dot). 

Again : A cylindrical piece of wood requires to be 
squared, and each side of the square must measure 
an inch : what diameter must the piece be turned to ? 

Now the diagonal line marked 45 degrees passes 
through the i-inch line on O B, and the inch line on 
O P, at the point where these lines meet ; hence all we 
have to do is to run the eye along either of the lines 
marked inch, and from its point of meeting the 45 de- 
grees line, to the point O, is the diameter to turn the 
piece to. 

There is another way, however, of getting this same 
measurement, which is to set a pair of compasses from 
the line i on O B, to line i on O P, as shown by the 
line D, which is the full diameter across corners. This 
is apparent, because from point O, along line O B, to 
I, thence to the dot, thence down to line i on O P, and 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. 13^ 

along that to O, encloses a square, of which either from 
O to the dot, or the length of the line D, is the meas- 
urement across corners, while the length of each side, 
or diameter across the flats, is from point O to either of 
the points i, or from either of the points i to the dot. 




Fig. 182. 

After graphically demonstrating the correctness of 
the scale we may simplify it considerably. In Figure 
182, therefore, we have applications shown. A is a 
hexacron, and if one of its sides be measured, it will 



j^S MECHANICAL DRAWING SELF-TAUGHT. 

be found that it measures the same as along line i 
from O B to the diagonal line 45 degrees, which dis- 
tance is shown by a thickened line. 

At I ^ is shown a seven-sided figure, whose diam- 
eter is 3 inches, and radius i^ inches, and if from the 
point at i^ (along the thickened horizontal line), to 
the diagonal marked 49 degrees, be measured, it will 
be found exactly equal to the length of a side on the 
polygon. 

At C is shown part of a nine-sided polygon, of 2- 
inch radius, and the length of one of its sides will be 
found to equal the distance from the diagonal line 
marked 52^ degrees, and the line O B at 2. 

Let it now be noted that if from the point O, as a 
centre, we describe arcs of circles from the points of 
division on O B to O P, one end of each arc will meet 
the same figure on O P as it started from at O B, as 
is shown in Figure 181, and it becomes apparent that in 
the length of diagonal line between O and the re- 
quired arc we have the radius of the polygon. 

Example. — What Is the radius across corners of a 
hexao^on or six-sided fiorure, the lencrth of a side beino[ 
an inch ? 

Turning to our scale we find .that the place where 
there is a horizontal distance of an inch between the 
diagonal 45 degrees, answering to six-sided figures, is 
along line i (Figure 182), and the radius of the circle 
enclosing the six-sided body is, therefore, an inch, as 
will be seen on referring to circle A. But it will be noted 
that the length of diagonal line 45 degrees, enclosed 
between the point O and the arc of circle from i on 
O B to one on O P, measures also an inch. Hence 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. 



139 



we may measure the radius along the diagonal lines 
if we choose. This, however, simply serves to de- 
monstrate the correctness of the scale, which, being 
understood, we may dispense with most of the lines, 
arriving at a scale such as shown in Figure 183, in 




Fig. 183. 

which the length of the side of the polygon is the dis- 
tance from the line O B, measured horizontally to the 
diagonal, corresponding to the number of sides of the 
polygon. The radius across corners of the polygon 
is that of the distance from O along O B to the hori- 
zontal line, giving the length of the side of the poly- 
gon, and the width across corners for a given length 
of one side of the square, is measured by the length 
of the lines A, B, C, etc. Thus, dotted line 2 shows 



140 



MECHANICAL DRAWING SELF-TAUGHT. 



the length of the side of a nine-sided figure, of 2- 
Inch radius, the radius across corners of the fio^ure 
being 2 inches. 

The dotted line 2 j^ shows the length of the side of a 
nine-sided polygon, having a radius across corners of 
2^ inches. The dotted line i shows the diameter, 
across corners, of a square whose sides measure an 
inch, and so on. 

This scale lacks, however, one element, in that the 
diameter across the flats of a regular polygon being 




Fig. 1S4. 

criven, it will not give the diameter across the corners. 
This, however, we may obtain by a somewhat simi- 
lar construction. Thus, in Figure 1S4, draw the line 
O B, and divide it into inches and parts of an 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. 141 



inch. From these pohits of division draw horizontal 
hnes; from the point O draw the following hnes and 
at the followincr angles from the horizontal line 

o p. 




£nd View 



Side View 



Fig. 185. 



A line at 75° for polygons having 12 sides. 

(( 72° " " 10 " 

60° " " 6 " 

From the point O to the numerals denoting the 
radius of the polygon is the radius across the flats, 
while from point O to the horizontal line drawn from 

I 




Fig. 186. 

those numerals is the radius across corners of the 
polygon. 



142 



MECHANICAL DRAWING SELF-TAUGHT. 



A hexagon measures two inches across the flats: 
what is its diameter measured across the corners? 
Now from point O to the horizontal hne marked i 
inch, measured along the line of 60 degrees, is i 
5-32nds inches: hence the hexagon measures twice 



^ 



Fig. 187. 

that, or 2 5-i6ths inches across corners. The proof 
of the construction is shown in the figure, the hex- 
agon and other polygons being marked simply for 
clearness of illustration. 



r\ 



Fig. 188. 

Let it be required to draw the stud shown In Fig- 
ure 185, and the construction would be, for the pencil 
lines, as shown in Fimire 186; line \ is the centre line, 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. 143 

arc6, 2 and 3 give the large, and arcs 4 and 5 the 
small diameter, to touch which lines 6, 7, 8, and 9 
may be drawn. Lines 10, 11, and 12 are then drawn 
for the lengths, and it remains to draw the curves in. 
In drawing these curves great exactitude is required 
to properly find their centres ; nothing looks worse in 
a drawing than an unfair or uneven junction between 
curves and straight lines. To find the location for 
these centres, set the compasses to the required radius 
for the curve, and from the point or corner A draw the 
arcs b and c, from c mark the arc e, and from b the 
arc d, and where d and e cross is the centre for the 
curvey^ 

B 




M 



'^ 



Fig. 189. 

Similarly for the curve h, set the compasses on l 
and mark the arc g, and from the point where it 
crosses line 6, draw the curve h. In inking in it is 
best to draw in all curves or arcs o{ circles first, and 
the straight lines that join them afterward, because, if 
the straight lines are drawn first, it is a difficult mat- 
ter to alter the centres of the curves to make them 



144 



MECHANICAL DRAWING SELF-TAUGHT. 



fall true, whereas, after the curves are drawn it is an 
easy matter, if it should be necessary, to vary the line 
a trifle, so as to make it join the curves correctly and 
fair. In inking in these curves also, care must be 




taken not to draw them too short or too long, as this 
would impair the appearance very much, as is shown 
in Figure 187. 




Fig. 191. 

To draw the piece shown in Figure 188, the lines 
are drawn in the order indicated by the letters in Fig- 
ure 189, the example being given for practice. It is 
well for the beginner to draw examples of common 
objects, such as the hand hammer in Figure 190, or the 
chuck plate in Figure 191, which afford good exam- 
ples in the drawing of arcs and circles. 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. 145 

Ipx Figure 191 ^ is a cap nut, and the order in which 
the same would be pencilled in is indicated by the re- 
specdve numerals. The circles 3 and 4 represent the 
thread. 




Fig. 191 ^ 



In Figure 192 is shown the pencilling for a link 
having the hubs on one side only, so that a centre line 



146 



MECHAMCAL DRAIVIXG SELF-TAUGHT. 



is unnecessary on the edge view, as all the lengths 
are derived from the top view, while the thickness of 
the stem and height of the hubs mav be measured 
from the line A. In Figure 193 there are hubs (on 



/ 




Fi< 



192. 



both sides of the link) of unequal height, hence a cen- 
tre line is necessary in both views, and from this line 
all measurements should be marked. 

In Figure 194 are represented the pencil lines for a 




Fig. 193. 

double eye or knuckle joint, as it is sometimes termed, 
an example that it is desirable for the student to draw 
in various sizes, as it is representative of a large class 
of work. 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. i^y 

These eyes often have an offset, and an example of 
this is given in Figure 195, in which A is the centre 



si 






7^ 



?r^ 



Fig. 194. 

line for the stem distant from the centre line B of the 
eyes to the amount of offset required. 




en 



Fig. 195- 

In Figure 196 is an example of a connecting rod 
d. From a point, as A, we draw arcs, as B C for 



the width, and E D for the leno^th of the block, and 
through A we draw the centre line. It is obvious, 
however, that we may draw the centre line first, and 



j.g MECHANICAL DRAWING SELF-TAUGHT. 

apply the measuring rule direct to the paper, and 
mark lines in place of the arcs B, C, D, E, and F, G, 
which are for the stem. As the block joins the stem 
in a straight line, the latter is evidently rectangular, 
as will be seen by referring to Figure 197, which rep- 



-f 



^^^ 



J 



:^^ 



r. 



o\ 



-1 



Fig. 196. 

resents a rod end with a round stem, the fact that the 
stem is round being clearly shown by the curves A B., 
The radius of these curves is obtained as follows : It 
is obvious that they will join the rod stem at the same 





'A 




( 


!/'' 







iX. 






, i^ 






D I ' E 




( 


1 .- . 


A 1 ' 1 



Fig. 197. 

point as the shoulder curves do, as denoted by the 
dotted vertical line. So likewise they join the curves 
E F at the same point in the rod length as the shoul- 
der curves, both curves in fact being formed by the 
same round corner or shoulder. The centre of the 



EXAMPLES IN BOLTS, NUTS, AND POLYGONS. 149 

radius of A or B must therefore be the same distance 
from the centre of the rod as is the centre from which 
the shoulder curve is struck, and at the same time at 
such a distance from the corner (as E or F) that the 
curve will meet the centre Hne of the rod at the same 
point in its length as the shoulder curves do. 

Figure 198 gives an example, in which the similar 







J 



.^nU 



/o 



Fig. 198. 

curved lines show that a part is square. The figure 
represents a bolt with a square under the head. As 
but one view is given, that fact alone tells us that it 
must be round or square. Now we might mark a 
cross on the square part, to denote that it is square ; 
but this is unnecessary, because the curves F G show 
such to be the case. These curves are marked as 
follows : With the compasses set to the radius E, one 
point is rested at A, and arc B is drawn ; then one 
point of the compass is rested at C, and arc D is 
drawn ; giving the centre for the curve F by a similar 



ISO 



MECHANICAL DRAWING SELF-TAUGHT. 



process on the other side of the figure, curve G is 
drawn. Point C is obtained by drawing the dotted 
line across where the outHne curve meets the stem. 
Suppose that the corner where the round stem meets 
the square under the head was a sharp one instead of 
a curve, then the traditional cross would require to be 
put on the square, as in Figure 199; or the cross will 





Fig. 199. 



Fig. 200. 



be necessary if the corner be a round one, if the stem 
is reduced in diameter, as in Figure 200. 

Figure 201 represents a centre punch, giving an 




201. 



example, in which the flat sides gradually run out 
upon a circle, the edges forming curves, as at A, B, 
etc. The length of these curves is determined as fol- 



EXAMPLES IX BOLTS, XUTS, AXD POLYGONS. 151 

lows: They must begin where the taper of the punch 
joins the parallel, or at G, C, and they must end on 
that part of the taper stem where the diameter is 
equal to the diameter across the flats of the octagon. 
All that is to be done then is to find the diameter 
across the flats on the end view, and mark it on the 
taper stem, as at D, D, which will show where the 
flats terminate on the taper stem. And the curved 
lines, as A, B, may be draw^n in by a curve that must 
meet at the line C, and also in a rounded point at 
line D. 



CHAPTER VIII. 

SCREW THREADS AND SPIRALS. 

The screw thread for small bolts is represented by 
thick and thin lines, such as was shown in Figure 152. 
but in larger sizes; the angles of the thread also arc 
drawn in, as in Figure 202, and the method of doing 
this is shown in Figure 203. The centre line i and 
lines 2 and 3 for the full diameter of the thread being 




Fig. 202. 

drawn, set the compasses to the required pitch of the 
thread, and stepping along line 2, mark the arcs 4, 
5, 6, etc., for the full length the thread is to be 
marked. With the triangle resting aeainst the T- 
square, the lines 7, 8, 9, etc. (for the full length of the 
thread), are drawn from the points 4, 5, 6, on line 2. 
These give one side of the thread. Reversing the 
drawing triangle, angles 10, 11, etc., are then 



SCREW THREADS AND SPIRALS. 



153 



drawn, which will complete the outline of the thread 
at the top of the bolt. We may now mark the depth 
of the thread by drawing line 12, and with the com- 




passes set on the centre line transfer this depth to the 
other side of the bolt, as denoted by the arcs 13 and 
14. Touching arc 14 we mark line 15 for the thread 



154 



MECHANICAL DRAWING SELF-TAUGHT. 



depth on that side. We have now to get the slant of 
the thread across the bolt. It is obvious that in 
passing once around the bolt the thread advances to 
the amount of the pitch as from a to b ; hence, in 
passing half way around, it will advance from a to c; 
we therefore draw line 1 6 at a right-angle to the cen- 
tre line, and a line that touches the top of the threads 
at ^, where it meets line 2, and also meets line 16, 
where it touches line 3, is the angle or slope for the 
tops of the threads, which may be drawn across by 
lines, as 18, 19, 20, etc. From these lines the sides of 
the thread may be drawn at the bottom of the bolt, 
marking first the angle on one side, as by lines 21, 22, 

23, etc., and then the angles on the other, as by lines 

24, 25, etc. 




Fig. 204. 

There now remain the bottoms of the thread to 
draw, and this is done by drawing lines from the bot- 
tom of the thread on one side of the bolt to the bot- 
tom on the other, as shown in the cut by a dotted line; 
hence, we may set a square blade to that angle, and 
mark in tliese lines, as 26, 27, 28, etc., and the thread 
^s pencilled in complete. 

If the student will follow out this example upon 



SCREW THREADS AND SPIRALS, 



155 



paper, it will appear to him that after the thread had 
been marked out on one side of the bolt, the angle of 
the thread might be obtained, as shown bylines 16 
and 1 7, and that the bottoms of the thread as well as 
th/" tops might be carried across the bolt to the other 




side. Figure 204 represents a case in which this has 
been done, and it will be observed that the lines de- 
noting the bottom of the thread do not meeC the bot- 
toms of the thread, which occurs for the reason that the 




angle for the bottom is not the same as that for the 
top of the thread. 

In inking in the thread, it enhances the appearance 
to give the bottom of the thread and the right-hand 



1^6 



MECHANICAL DRAWING SELF-TAUGHT. 



side of the same, heavy shade lines, as in Figure 202, 
a plan that is usually adopted for threads of large di- 
ameter and coarse pitch. 

A double thread, such as in Figure 205, is drawn in 
the same way, except that the slant of the thread is 
doubled, and the square is to be set for the thread- 
pitch A, A, both for the tops and bottoms of the 
thread. 

A round top and bottom thread, as the Whitworth 




Fig. 207. 

thread, is drawn by single lines, as in Figure 206. 
A left-hand thread, Figure 207, is obviously drawn by 
die same process as a right-hand one, except that the 
slant of the thread is given in the opposite direction. 

For screw threads of a larcre diameter it is not un- 
common to draw in the thread curves as they appear 
to the eye, and the method of doing this is shown in 
Fio^ure 208. The thread is first marked on both sides 
of the bolt, as explained, and instead of drawing, 
straight across the bolt, lines to represent the tops 
and bottoms of the thread, a template to draw the 
curves by is required. To get these curves, two half- 
circles, one equal in diameter to the top, and one 



SCREW THREADS AND SPIRALS. 



157 



equal to the bottom of the thread, are drawn, as in 
Fiofure 208. 

These half-circles are divided Into any convenient 
number of equal divisions: thus In Figure 208, each has 
eight divisions, as a, b, c, etc., for the outer, and i, /, k^ 
etc., for the inner one. The pitch of the thread is 



hcdc/ijh ijli fnitii) 




Fig. 208. 

then divided off by vertical lines into as many equal 
divisions as the half-circles are divided into, as by 
the lines a, b, c, etc., to 0. Of these, the seven from a, 
to h, correspond to the seven from o! to g\ and are 
for the top of the thread, and the seven from i to 
correspond to the seven on the inner half-circle, as ?', 
y, k, etc. Horizontal lines are then drawn from the 



iqg MECHANICAL DRAWING SELF-TAUGHT. 

points of the division to meet the vertical Hnes of di- 
vision; thus the horizontal dotted line from a! meets 
the vertical line a, and where they meet as at A, a dot 
is made. Where the dotted line from b' meets verti- 
cal line b, another dot is made., as at B, and so on 
until the point G is found. A curve drawn to pass 
from the top of the thread on one side of the bolt to 
the top of the other side, and passing through these 
points, as from A to G, will be the curve for the top 
of the thread, and from this curve a template may be 
made to mark all the other thread-tops from, because 
manifestly all the tops of the thread on the bolt will 
be alike. 

For the bottoms of the thread, lines are similarly 
dra\yn, as from }' to meet ?', where dot I is marked. J is 
got from/' andy, while K is got from the intersection of 
k' with k, and so on, the dots from I to O being those 
through which a curve is drawn for the bottom of the 
thread, and from this curve a template also may be 
made to mark all the thread bottoms. We have in 
our example used eight points of division in each 
half-circle, but either more or less points maybe used, 
the only requisite being that the pitch of the thread 
must be divided into as many divisions as the two half- 
circles are. But it is not absolutely necessary that 
both half-circles be divided into the same number of 
equal divisions. Thus, suppose the large half-circle 
were divided into ten divisions, then instead of the first 
half of the pitch being divided into eight (as from a 
to Ji) it would require to have ten lines. But the 
inner half-circle may have eight only, as in our ex- 
ample. It is more convenient, however, to use the 



SCREW THREADS AND SPIRALS. 



159 



same number of divisions for both circles, so that 
they may both be divided together by lines radiating 
from the centre. The more the points of division, the 
greater number of points to draw the curves through; 
hence it is desirable to have as many as possible, 
which is governed by the pitch of the thread, it being 
obvious that the finer the pitch the less the number of 
distinct and clear divisions it is practicable to divide 
it into. In our example the angles of the thread are 
spread out to cause these lines to be thrown further 
apart than they would be in a bolt of that diameter; 
hence it wall be seen that in threads of but two or 
three inches in diameter the lines would fall very 
close together, and would require to be drawn finely 
and with care to keep them distinct. 

The curves for a United States standard form of 
thread are obtained in the same manner as from the 
V thread in Figure 208, but the thread itself is more 
difficult to draw. The construction of this thread is 
shown in Figure 208, it having a flat place at the top 
and at the bottom of the thread. A common V thread 
has its sides at an angle of 60 degrees, one to the 
other, the top and bottom meeting in a point. The 
United States standard Is obtained from drawlne a 
common V thread and dividing its depth Into eight 
equal divisions, as at x, in Figure 208 a, and cutting 
off one of these divisions at the top and filling in one 
at the bottom to form flat places, as shown in the figure. 
But the thread cannot be sketched on a bolt by this 
means unless temporary lines are used to get the 
thread from, these temporary lines being drawn to 
represent a bolt one-fourth the depth of the thread too 



i6o 



MECHANICAL DRAWING SELF-TAUGHT, 



large in diameter. Thus, in Figure 208 a, it is seen 
that cutting off one-eighth the depth of the thread re- 
duces the diameter of the thread. It is necessary, 
then, to draw the flat place on top of the thread first, 

"ilTlfi^lrMJl II jl! 




Fig. 208 a. 

the order of procedure being, shown in Figure 209. 
The lines for the full diameter of the thread being 




Fig. 209. 

drawn, the pitch is stepped off by arcs, as 1,2, 3, etc., 
and from these, arcs, as 4, 5, 6, etc., aie marked for 
the width of the flat places at the tops of the threads. 



SCREW THREADS AND SPIRALS. i6l 

Then one side of the thread is marked off by lines, as 
7, which meet the arcs i, 2, 3, etc., as at a, c, etc. 
Similar lines, as 8 and 9, are marked for the other 
side of the thread, these lines, 7, 8 and 9, projecting 
until they cross each other. Line 10 is then drawn, 
making a flat place at the bottom of the thread equal 
in width to that at the top. Line 12 is then drawn 
square across the bolt, starting from the bottom of the 
thread, and line 13 is drawn starting from the corner 
/on one side of the thread and meeting line 12 on 
the other side of the thread, which gives the angle for 
the tops of the thread. The depth of the thread may 
then be marked on the other side of the bolt by the 
arcs d and e, and the line 14. The tops of all the 
threads may then be drawn in, as by lines 15, 16, 17 
and 18, and by lines, as 19, etc., the thread sides may 
be drawn on the other side of the bolt. All that re- 
mains is to join the bottoms of the threads by lines 
across the bolt, and the pencil lines will be complete, 
ready to ink in. If the thread is to be shown curved 
instead of drawn straiglit across, the curve may be 
obtained by the construction in Figure 208, which is 
similar to that in Figure 207. except that while the 
pitch is divided off into 1 6 divisions, the whole of these 
16 divisions are not used to get the curves, some of 
them being used twice over; thus for the bottom the 
eight divisions from b to z are used, while for the tops 
the eight from ^ to are \4sed. Hence g, h and i are 
used for getting both curves, the divisions from ^ to ^ 
and from <? to/ being taken up by the fiat top and 
bottom of the thread. It will be noted that in Fieure 
207, the top of the thread is drawn first, while in Fig- 



1 62 



MECHANICAL DRA WING SELF- TA UGHT. 



ure 208 the bottom is drawn first, and that in the 
latter (for the U. S. standard) the pitch is marked 
from centre to centre of the flats of the thread. 

To draw a square thread the pencil lines are marked 
in the order shown in Figure 210, in which i repre- 




Fig. 210. 



sents the centre line and 2, 3, 4 and 5, the diameter 
and depth of the thread. The pitch of the thread is 
marked off by arcs, as 6, 7, etc., or by laying a rule di- 
rectly on the centre line and marking with a lead pen- 
cil. To obtain the slant of the thread, lines 8 and 9 
are drawn, and from these line 10, touching 8 and 9 
where they meet lines 2 and 5 ; the threads may then 
be drawn in from the arcs as 6, 7, etc. The side of 
the thread will show at the top and the bottom as at 
A B, because of the coarse pitch and the thread on 
the other or unseen side of the bolt slants, as denoted 
by the lines 12, 13 ; and hence to draw the sides A B, 
the triancrle must be set from one thread to the next 
on the opposite side of the bolt, as denoted by the 
dotted lines 12 and 13. 

If the curves of the thread are to be drawn in, they 



XREIV THREADS AND SPIRALS. 



163 



may be obtained as in Figure 211, which is substan- 
tially the same as described for a V thread. The 
curves / representing- the sides of the thread, termi- 




nate at the centre line g, and the curves e are equi- 
distant with the curves c from the vertical lines d. As 



1 64 



MECHANICAL DRAWIXG SELF-TAUGHT. 



the curves f above the line are the same as f below 
the line, the template for f need not be made to ex- 
tend the whole distance across, but one-half only; as 




is shown by the dotted curve g, in the construction for 
finding the curve for square-threaded nuts in Figure 

212. 



SCSEIV THREADS AXD SPIRALS. 



165 



A specimen of the form of template for drawing 
these curves is shown in Figure 213 ; g g, is the cen- 
tre Hne parallel to the edges R, S ; lines m, n, repre- 
sent the diameter of the thread at the top, and 0, p, 
that at the bottom or root ; edge a is formed to the 
points (found by the constructions in the figures as 
already explained) for the tops of the thread, and edge 
/ is so formed for the curve at the thread bottoms. 
The edge, as S or R, is laid against the square-blade 




1 I 



Fig. 213. 

to steady it while drawing in the curves. It may be 
noted, however, that since the curve is the same below 
the centre line as it is above, the template may be made 
to serve for one-half the thread diameter, as ^Xf, where 
it is made from o to g, only being turned upside down 
to draw the other half of the curve ; the notches cut 
out at X, Xy are merely to let the pencil-lines in the 
drawing show plainly when setting the template. 



J 56 MECHANICAL DRAWING SELF-TAUGHT. 

When the thread of a nut is shown in section, it 
slants in the opposite direction to that which appears 
on the bolt-thread, because it shows the thread that 
fits to the opposite side of the bolt, which, therefore, 
slants in the opposite direction, as shown by the lines 
12 and 13 in Figure 210. 

In a top or end view of a nut the thread depth is 
usually shown by a simple circle, as in Ffgure 214. 




Fig. 214. 

To draw a spiral spring, draw the centre line A, and 
lines B, C, Figure 215, distant apart the diameter 
the spring is to be less the diameter of the wire of 
which it is to be made. On the centre line A mark 
two lines ab, c d, representing the pitch of the spring. 
Divide the distance between a and b into four equal di- 
visions, as by lines i, 2, 3, letting line 3 meet line B. 
Line e meeting the centre line at line a, and the line 
B at its intersection with line 3, is. the angle of the 
coil on one side of the spring ; hence it may be marked 
in at all the locations, as at ef, etc. These lines give 
at their intersections with the lines C and B the cen- 
tres for the half circles g, which being drawn, the sides 
//, z,y, k, etc., of the spring, may all be marked in. By 
the lines m, 11, 0, p, the other sides of the spring may 
be marked in. 



SCREW THREADS AND SPIRALS. 



167 



The end of the spring is usually marked straight 
across, as at L. If it is required to draw the coils 
curved instead of straight across, a template must be 

obtained as already described 



made, the curve beine 




for threads. It may be pointed out, however, that to 
obtain as accurate a division as possible of the lines 
that divide the pitch, the pitch may be divided upon 



i6S 



MECHAXICAL DRAIVIXG SELF-TAUGHT. 



a diagonal line, as F, Figure 216, which will greatly 
facilitate the operation. 




Fig. 216. 



Before going into projections it may be as well to 
give some examples for practice. 




Brasses for h 



Fisf. 2I<* 



Sole for Set-Screw yll Tapped 14 'Threads 



Front Elevation of 
Hod, without Brass. 



^ I 



7 



rough C- D^ 



mds ivill be cast from the same patterns. 

SCALE OF INCHES. 




Back lElevaticn of Brass 



(Page 169.) 



CHAPTER IX. 

EXAMPLES FOR PRACTICE. 

Figure 217 represents a simple example for prac- 
tice, which the student may draw the size of the en- 
graving, or he may draw it twice the size. It is a 




locomotive spring, composed of leaves or plates, held 
together by a central band. 

Figure 218 is an example of a stuffing box and 
gland, supposed to stand vertical, hence the gland has 
an oil cup or receptacle. 

In Figure 219 are working drawings of a coupling 
rod, with the dimensions and directions marked in. 

It may be remarked, however, that the drawings of 
a workshop are, where large quantities of the same 
kind of work is done, varied in character to suit some 
special departments — that is to say, special extra draw- 
ings are made for these departments. In Figures 
220 and 221 is a drawing of a connecting rod drawn, 
put together as it would be for the lathe, vise or erect- 
ing- shop. 
^ ^ (169) 



I/O 



iMECHAXICAL DRAWING SELF-TAUGHT. 





^^=i^iyjLyj Fig. 220. 



p^ 7 






Fig. 221. 



EXAMPLES FOR PRACTICE. 



171 



To the two views shown there would be necessary 
detail sketches of the set screws, gibbs, and keys, all 
the rest being shown ; the necessary dimensions being, 
of course, marked on the general drawino^ and on tlie 
details. 

In so simple a thing as a connecting rod, however, 
there would be no question as to how the parts go 
together; hence detail drawings of each separate piece 
would answer for the lathe or vise bands. 

But in many cases this would not be the case, and 
the drawing would require to show the parts put to- 
gether, and be accompanied with such detail sketches 
as might be necessary to show parts that could not be 
clearly defined in the general views. 

The blacksmith, for example, is only concerned 
with the making of the separate pieces, and has no 
concern as to how the parts go together. Further- 
more, there are parts and dimensions in the general 
drawinor with which the blacksmith has nothinor to do. 

Thus the location and dimensions of the keyways, 
the dimensions of the brasses, and the location of the 
bolt holes, are matters that have no reference to the 
blacksmith's work, because the keyways, bolt holes, 
and set-screw holes would be cut out of the solid in 
the machine shop. It is customary, therefore, to send 
to the blacksmith shop drawings containing separate 
views of each piece drawn to the shape it is to be 
forged ; and drawn full size, or else on a scale suffi- 
ciently large to make each part show clearly without 
close inspection, marking thereon the full sizes, and 
stating beneath the number of pieces of each detail. 
(As in Figure 222, which represents the iron work of 



172 



MECHANICAL DRAWING SELF-TAUGHT. 



ONE THUS. 




ONE THUS. 



"=^ r 



i L 



ONE THUS. 



u 



Li. U 



three thus, 
(cast steel.) 



TWO THUS. TWO THUS. 
Fig. 222 



ONE THUS. 



EXAMPLES FOR PRACTICE. 



1/3 



the connecting rod in Figure 220). In some cases 
the finished sizes are marked, and it is left to the 
blacksmith's judgment how much to leave for the fin- 
ishing. This is undesirable, because either the black- 
smith is left to judge what parts are to be finished, or 
else there must be on the drawing instructions on this 
point, or else signs or symbols that are understood to 
convey the information. It is better, therefore, to 
make for the blacksmith a special sketch, and mark 
thereon the full-forged sizes, stating on the drawing 
that such is the case. 

As to the material of which the pieces are to be 
made, the greater part of blacksmith work is made of 
wrought iron, and it is, therefore, unnecessary to write 
"wrought iron" beneath each piece. When the pieces 
are to be of steel, however, it should be m.arked on 
the drawing and beneath the piece. In special cases, 
as where the greater part of the work of the shop is 
of steel, the rule may, of course, be reversed, and the 
parts made of iron may be the ones marked, whereas 
when parts are sometimes of iron, and at others of 
steel, each piece should be marked. 

As a general rule the blacksmith knows, from the 
custom of the shop or the nature of the work, what 
the quality or kind of iron is to be, and it is, therefore, 
only in exceptional cases that they need to be men- 
tioned on the drawinor. Thus in a carriao-e manufac- 

o o 

tory, Norway or Swede iron will be found, as well as 
the better grades of refined iron, but the blacksmith 
will know what iron to use, for certain parts, or the 
shop may be so regulated that the selection of the 
iron is not left to him. In markinor the number of 



jy. MECHANICAL DRAWING SELF-TAUGHT, 

pieces required, it is better to use the word "thus" 
than the words " of this," or " off this," because it is 
shorter and more correct, for the forging is not taken 
off the drawing, nor is it of the same ; the drawing 
gives the shape and the size, and the word "thus" 
conveys that idea better than " of," " off," or " Hke 
this." 

In shops where there are many of the same pieces 
forced, the blacksmith is furnished with sheet-iron 
templates that he can lay directly upon the forging 
and test its dimensions at once, which is an excellent 
plan in large work. Such templates are, of course, 
made from the drawings, and it becomes a question 
as to whether their dimensions should be the forged 
or the finished ones. If they are the forged, they may 
cause trouble, because a forging may have a scant 
place that it is difficult for the blacksmith to bring up 
to the size of the template, and he is in doubt whether 
there is enough metal in the scant place to allow the 
job to clean up. It is better, therefore, to make them 
to finished sizes, so that he can see at once if the work 
will clean up, notwithstanding the scant place. This 
will lead to no errors in large work, because such 
work Is marked out by lines, and the scant part will 
therefore be discovered by the machinist, who will 
line out the piece accordingly. 

Figure 223 is a drawing of a locomotive frame, 
which the student may as well draw three or four 
times as large as the engraving, which brings us to 
the subject of enlarging or reducing scales. 



EXAMPLES FOR PRACTICE. 



75 



REDUCING SCALES. 

It is sometimes necessary to reduce a drawing to a 




sp^aller scale, or to find a minute fraction of a given 



176 



MECHANICAL DRAWING SELF-TAUGHT. 



dimension, such fraction not being marked on the 
h'neal measuring rules at hand. Figure 224 repre- 
sents a scale for findincr minute fractions. Draw 
seven lines parallel to each other, and equidistant 
draw vertical lines dividine the scale into half inches, 



.A. 


4/ N^c . 






3/ \"o i 






2 / \lO 1 






1/' \ll 


1 1 


^ 


i 1 



Fig. 224. 

as at a, b, c, etc. Divide the first space e d into 
equal halves, draw diagonal lines, and number them 
as in th(^. figure. The distance of point i, which is at 
the intersection of diaoronal with the second horizontal 



c 


J 




2 


i 


4 


\ 




1 




) 1. 

1 


D 




/ 


1 


1 


\ 


. 


1 




I 


I 








1 


/ 


1 


\ 


1 
1 


i 


I 


i 


\ 


/ 






/ 


1 


1 


1 


1 




I 


1 


\ 








\ 


1 


( 


1 




\ 
















1 


/ 


1 


1 


\ 


1 




\ 


1 


1 






1 


I 


J_n 


Ml 


\ 


1 


\ 


1 








1 


i 


1 


\ 


\ 


1 


I 










I 

1 




i 


\ 


\ 




j 


\ 












' 1 






\ 




'- 


'■ 


1) 



Fig. 225. 

line, will be 2'? inch from vertical line e. Point 2 will 
be -fi inch from line c, and so on. For tenths of inches 
there would require to be but six horizontal lines, the 
diao-onals beino; drawn as before. A similar scale is 
shown in Figure 225. Draw the lines A B, B D, D C, 



EXAMPLES FOR PRACTICE. 



^71 



C A, enclosing a square inch. Divide each of these lines 
into ten equal divisions, and number and letter them as 
shown. Draw also the diagonal lines A i, ^ 2, B 3, 
and so on ; then the distances from the line A C to 
the points of intersection of the diagonals with the 
horizontal lines represent hundredths of an inch. 

Suppose, for example, we trace one diagonal line in 
its path across the figure, taking that which starts from 
A and ends at i on the top horizontal line ; then where 
the diagonal intersects horizontal line i, is .^^o from 
the line B D, and ^^ from the line A C, while where it 
intersects horizontal line 2, is t>o fi^om line B D, and 
joo from line A C, and so on. If we require to set the 
compasses to ll, inch, we set them to the radius of n. 
and the figure 3 on line B D, because from that 3 to 
the vertical line <2f 4 is l^ or ,o°o inch, and from that 
vertical line to the diagonal at n is seven divisions 
from the line. C D of the figure. 

In making a drawing to scale, however, it is an ex- 
cellent plan to draw a line and divide it off to suit the 
required scale. Suppose, for example, that the given 
scale is one-quarter size, or three inches per foot ; then 
a line three inches long may be divided into twelve 
equal divisions, representing twelve inches, and these 
may be subdivided into half or quarter inches and so 
on. It is recommended to the beginner, however, to 
spend all his time making simple drawings, without 
making them to scale, in order to become so familiar 
with the use of the instruments as to feel at home 
with them, avoiding the complication of early studies 
that would accompany drawing to scale. 



CHAPTER X. 
PROJECTIONS. 

In projecting, the lines in one view are used to 
mark those in other views, and to find their shapes or 
curvature as they will appear in other views. Thus, 
in Figure 2Z^a we have a spiral, v:ound around a cyl- 
inder whose end is cut off at an angle. The pitch of 
the spiral is the distance A B, and we may delineate 
the curve of the spiral looking at the cylinder from 
two positions (one at a right-angle to the other, as is 
shown in the figure), by means of a circle having a 
circumference equal to that of the cylinder. 

The circumference of this circle we divide into any 
number of equidistant divisions, as from i to 24. 
The pitch A B of the spiral or thread is then divided 
off also into 24 equidistant divisions, as marked on 
the left hand of the figure; vertical lines are then 
drawn from the points of division on the circle to the 
points correspondingly numbered on the lines dividing 
the pitch; and where line i on the circle intersects 
line I on the pitch is one point in the curve. Sim- 
ilarly, where point 2 on the circle intersects line 2 on 
the pitch is another point in the curve, and so on for 
the whole 24 divisions on the circle and on the pitch, 
in this view, however, the path of the spiral from line 
7 to line 19 lies on the other side of the cylinder, and 
is marked in dotted lines, because it is hidden by the 
(17S) 



PR OJECTIONS. I ^Q 

cylinder. In the right-hand view, however, a different 








ill' fl' .' I ' I 
^-441 — ' / / / 

r— - y / / I I I I 
la...--' / / / / //' 



./ // 



/ / ''r 



Fig. 225 «. 
portion of the spiral or thread is hidden, namely from 



J So MECHANICAL DRAWING SELF-TAUGHT. 

lines I to 13 inclusive, being an equal proportion to 
that hidden in the left-hand view. 

The top of the cylinder is shown in the left-hand 
view to be cut off at an angle to the axis, and will 
therefore appear elliptical ; in the right-hand view, to 
delineate this oval, the same vertical lines from the 
circle may be carried up as shown on the right hand, 
and horizontal lines may be drawn from the inclined 
face in one view across the end of the other view, as 
at P; the divisions on the circle may be carried up on 
the right-hand view by means of straight lines, as Q, 
and arcs of circle, as at R, and vertical lines drawn 
from these arcs, as line S, and where these vertical 
lines S intersect the horizontal lines as P, are points 
in the ellipse. 

Let it be required to draw a cylindrical body join- 
ing another at a right-angle ; as for example, a Tee, 
such as in Figure 226, and the outline can all be 
shown in one view, but it is required to find the line 
of junction of one piece. A, with the other, B ; that is, 
find or mark the lines of junction C. Now when the 
diameters of A and B are equal, the line of junction C 
is a straight line, but it becomes a curved one when 
the diameter of A is less than that of B, or vice versa; 
hence it may be as well to project it in both cases. 
For this purpose the three views are necessary. One- 
quarter of the circle of B, in the end view, is divided 
off into any number of equal divisions ; thus we have 
chosen the divisions marked a, b, c, d, e, etc. ; a 
quarter of the top view is similarly divided off, as at 
f, ,^, h, 7, j ; from these points of division lines are 
projected on to the side view, as shown by the dotted 



PROJECTIONS. 



I8l 



lines k, /, in, n, o, p, etc., and where these Hnes meet, 
as denoted by the dots, is in each case a point in the 
line of junction of the two cylinders A, B. 



End View 




Side View 



Top View 



Fig. 226. 

Figure 227 represents a Tee, in which B is less in 
diameter than A; hence the two join in a curve, which 
is found in a similar manner, as is shown in Figure 



l82 



MECHANICAL DRAWING SELF-TAUGHT. 



227. Suppose that the end and top views are drawn, 
and that the side view is drawn in outline, but that 
the curve of junction or intersection is to be found. 




Tap View 



Fig. 227. 



Now it is evident that since the centre line i passes 
through the side and end views, that the face a, in the 



PR OJE C TIONS. 1 3 2 

end view, will be even with the face cc in the side view. 
both being the same face, and as the full length of the 
side of B in the end view is marked by line b, there- 
fore line c projected down from b will at its junction 
with line b\ which corresponds to line b, give the ex- 
treme depth to which b' extends into the body A, and 
therefore, the apex of the curve of intersection of B 
with A. To obtain other points, we divide one-quarter 
of the circumference of the circle B in the top view 
into four 'equal divisions, as by lines d, e,f, and from 
the points of division we draw lines/, i, g, to the centre 
line marked 2, these lines being thickened in the cut 
for clearness of illustration. The compasses are 
then set to the length of thickened line g, and from 
point h, in the end view, as a centre, the arc g' is 
marked. With the compasses set to the length of 
thickened line i, and from h as a centre, arc i' is 
marked, and with the length of thickened line J as a 
radius and from h as a centre arc/' is marked; from 
these arcs lines k, /, m are drawn, and from the intersec- 
tion of k, /, m, with the circle of A, lines n, o, p are let 
fall. From the lines of division, dy e^f^ the lines q, r, s 
are drawn, and where lines n, <?, / join lines q, r, s, are 
points in the curve, as shown by the dots, and .by 
drawing a line to intersect these dots the curve is 
obtained on one-half of B. Since the axis of B is in 
the same plane as that of A, the lower half of the 
curve is of the same curvature as the upper, as is 
shown by the dotted curve, 

• In Figure 228 the axis of piece B is not in the same 
plane as that of D, but to one side of it to the dis- 
tance between the centre lines C, D, which is mos'. 



j3_i mechanical drawing self-taught. 

clearly seen in the top view. In this case the procesj^ 
is the same except in the following points : In the 
side view the line w, corresponding to the line w in the 





'End 


View 




• 






/ 


P 


A 


\ 






/ 

/ 


V 


r» 


1 




\ 










\ 


u 




A " 






\ 


/i 1 

All 


h 


_-^ 




\ 


i 


_^d' 








/i ' ' ' 


<^ , 






-^''^ 1 ' 1 1 •' Ic 






















1 1 |ii 

\ \ \v\ 

Am 








C 




A 

1 


L- 


' ' 1 1 
1 ? ' li 

m \ 111 

; 1 I M 

1 1 :-- 


X 




D 




B^ 


A 

\ 





-•^"--J- - 


\A^ ' ■ t> 








^^ a 


1 1" ^ 




./ 


o. 


r * 




7'^ 


7, 












B 


V 






y 










D 




Side 


View 












c 







Fig. 22c 



Top View 



end view, passes within the line x before the curve of 
intersection becrins, and in transferring- the lencrths of 



PROJECIIOXS. 



185 



the full lines b, c, d, e, f, to the end view, and mark- 
ing the arcs b\ d, d\ e', f' they are marked from the 
point w (the point where the centre line of B inter- 
sects the outline of A), instead of from the point x. 
In all other respects the construction is the same as 
that in Figure 227. 



End View 




SideWiew 

Fig. 229. 

In these examples the axis of B stands at a right- 
angle to that of A. But in Figure 229 is shown the 
construction where the axis of B is not at a rieht- 



J 35 MECHANICAL DRAWING SELF-TAUGHT. 

angle to A. In this case there is projected from B, in 
the side view, an end view of B as at B i, and across 
this end at a riorht-ancrle to the centre Hne of B is 

o o 

marked a centre Hne C C of B', which is divided 
as before by Hnes d, e, f, g, //, their respective 
leno^ths beinor transferred from W as a centre, and 
marked by the arcs d\ el fl which are marked on a 
vertical line and carried by horizontal lines, to the arc 
of A as at i,j, k. From these points, z, y, k, the perpen- 
dicular lines /, m, n, o, are dropped, and where these lines 
meet lines/', q, r, s, t, are points in the curve of inter- 
section of B with A. It will be observed that each of 
the lines m, 7i, o, serves for two of the points in the 
curve ; thus, m meets q and s, while 7i meets/ and t, and 
meets the outline on each side of B, in the side view, 
and as /, 7, k are obtained from d and e, the lines 
g and h might have been omitted, being inserted 
merely for the sake of illustration. 

In Figure 230 is an example in which a cylinder in- 
tersects a cone, the axes being parallel. To obtain 
the curve of intersection in this case, the side view is 
divided by any convenient number of lines, as a, b, c, 
etc., drawn at a right-angle to its axis A A, and from 
one end of these lines are let fall the perpendiculars 
fygy K hj >' from the ends of these (where they meet 
the centre line of A in the top view), half-circles /-, /, ;;^, 
n, 0, are drawn to meet the circle of B in the top view, 
and from their points of intersection with B, lines /, 
q, r, s, /, are drawn, and where these meet lines a, b, c, 
d and e, which is at ?/, v, w, x, y, are points in the curve. 

It will be observed, on referrinof aeain to Figure 220, 
that the brancli or cylinder B appears to be of ellipti- 



PR OJE C TIONS. 1 8 J 

cal section on its end face, which occurs because it is 
seen at an angle to its end surface ; now the method 




Top View 

Fig. 230. 



of finding the elHpse for any given degree of an.o-le is 



i88 



MECHANICAL DRAWING SELF-TAUGHT. 



as In Figure 231, in which B represents a cyHndrical 
body whose top face would, if viewed from point I, ap- 
pear as a straight line, while if viewed from point J it 
would appear in outline a circle. Now if viewed from 
point E its apparent dimension in one direction will 
obviously be defined by the lines S, Z. So that if on a 
line G G at a riorht anorle to the line of vision E, we 
mark points touching lines S, Z, we get points i and 2, 
representing the apparent dimension in that direction 




Fig. 231. 

which is the width of the ellipse. The length of the 
ellipse will obviously be the full diameter of the cyl- 
inder B ; hence from E as a centre we mark points 3 
and 4, and of the remaining points we will speak 
presently. Suppose now the angle the top face of B 
is viewed from is denoted by the line L, and lines S', Z, 
parallel to L, will be the width for the ellipse whose 
length is marked by dots, equidistant on each side 
of centres line G' G', which equal in their widths one 



PR OJECTIOXS. 1 89 

from the other the full diameter of B. In this con- 
struction the ellipse will be drawn away from the cyl- 
inder B, and the ellipse, after being found, would have 
to be transferred to the end of B. But since centre 
line G G Is obviously at the same angle to A A that 
A A Is to G G, we may start from the centre line of 
the body whose elliptical appearance Is to be drawn, 
and draw a centre line A A at the same angle to G G 
as the end of B Is supposed to be viewed from. This 
is done In Figure 231 a, in which the end face of B is 
to be drawn viewed from a point on the line G G, but 
at an angle of 45 degrees; hence line A A is drawn 
at an angle of 45 degrees to centre line G G, and 
centre line E is drawn from the centre of the end of B 
at a right angle to G G, and from where It cuts A A, as 
at F, a side view of B is drawn, or a sinorle line of a 
length equal to the diameter of B may be drawn at a 
right angle to A A and equidistant on each side of F. 
A line, D D, at a right angle to A A, and at any conve- 
nient distance above F, is then drawn, and from its in- 
tersection with A A as a centre, a circle C equal to the 
diameter of B Is drawn; one-half of the circumference 
of C is divided off into any number of equal divi- 
sions as by arcs a, b, c, d, e, f. From these points of 
division, lines g, h, i, j\ k, I are drawn, and also lines 
;?2, n, 0, p, q, r. From the intersection of these last 
lines with the face In the side view, lines s, t, u, v, w, x, 
y, z diVQ drawn, and from point F line E is drawn. Now 
it is clear that the width of the end face of the cylinder 
will appear the same from any point of view it may be 
looked at, hence the sides H H are made to equal the 
diameter of the cylinder B and marked up to centre 
line E. 



1 90 



MECHANICAL DRAWING SELF-TAUGHT. 



It Is obvious also that the lines s, z, drawn from the 
extremes of the face to be projected will define the 




/)' A /yA / X' 




Fig. 231 a. 

width of the ellipse, hence we have four of the points 
\marked respectively i, 2, 3, 4) in the ellipse. To ob- 



PROJECTIOXS. IQI 

tain the remaining points, lines /, u, v, w, x, y (which 
start from the point on the face F where the Hnes m, 
n, o, p, q. r, respectively meet it) are drawn across the 
face of B as shown. The compasses are then set to 
the radius g; that is, from centre line D to division a 
on the circle, and this radius is transferred to the face 
to be projected the compass-point being rested at the 




intersection of centre line G and line /, and two arcs 
as 5 and 6 drawn, giving two more points in the curve 
of the ellipse. The compasses are then set to the 
length of line h (that is, from centre line D to point 
of division b), and this distance is transferred, setting 
the compasses on centre line G where it is intersected 



jg2 MECHANICAL DRAWING SELF-TAUGHT. 

by line u, and arcs 7, 8 are marked, giving two more 
points in the ellipse. In like manner points 9 and 10 
are obtained from the length of line ?, 1 1 and 1 2 from 
that oi j ; points 13 and 14 from the length oik, and 
1 5 and 1 6 from /, and the ellipse may be drawn in from 
these points. 

It may be pointed out, however, that since points 5 
and 6 are the same distance from G that points 1 5 
and 16 are, and since points 7 and 8 are the same 
distance from G that points 13 and 14 are, while 
points 9 and 10 are the same distance from G that 1 1 
and 1 2 are, the lines/, k, I are unnecessary, since / and 
g are of equal length, as are also h and k and i and/. 
In Figure 232 the cylinders are line shaded to make 
them show plainer to the eye, and but three lines (a, 
b, c) are used to get the radius wherefrom to mark 
the arcs where the points in the ellipse shall fall ; thus, 
radius a gives points i, 2, 3 and 4; radius b gives 
points 5, 6, 7 and 8, and radius c gives 9, 10, 11 and 
1 2, the extreme diameter being obtained from lines S, 
Z, ^nd H, H. 



CHAPTER XI. 

DRAWING GEAR WHEELS. 

The names given to the various lines of a tooth on 
a gear wheel are as follows : 

In Figure 233, A Is the face and B the flank of a 
tooth, while C is the point, and D the root of the 




Fig. 233. 

tooth; E is the height or depth, and F the breadth. 
P P is the pitch circle, and the space between the two 
teeth, as H, is termed a space. 

It is obvious that the points of the teeth and the 
13 (193) 



194 



MECHANICAL DRAWING SELF-TAUGHT. 



bottoms of the spaces, as well as the pitch circle, are 
concentric to the axis of the wheel bore. And to 
pencil in the teeth these circles must be fully drawn, 




as in P'igure 234, in which P P is the pitch circle. 
This circle is divided into as many equal divisions as 



DRAWING GEAR WHEELS. 



195 



the wheel is to have teeth, these divisions being 
denoted by the radial lines, A, B, C, etc. Where 
these divisions intersect the pitch circle are the centres 
from which all the teeth curves may be drawn. The 
compasses are set to a radius equal to the pitch, less 
one-half the thickness of the tooth, and from a 
centre, as R, two face curves, as F G, may be marked ; 
from the next centre, as at S, the curves D E may be 
marked, and so on for all the faces ; that is, the too:h 
curves lying between the outer circle X and the pitch 
circle P. For the flank curves, that is, the curve from 
P to Y, the compasses are set to a radius equal to the 
pitch; and from the sides of the teeth the flank curves 
are drawn. Thus from ], as a centre flank, K is drawn ; 
from V, as a centre flank, H is drawn, and so on. 

The proportions of tlie teeth for cast gears generally 
accepted in this country are those given by Professor 
WiUis, as average practice, and are as follows: 

Depth to pitch line, 
Working dei)th, 
Whole depth, 
Thickness of tooth, 
Breadth of space, 

Instead, however, of calculating the dimensions 
these proportions give for any particular pitch, a dia- 
gram or scale may be made from which they may be 
taken for any pitch by a direct application of the 
compasses. A scale of this kind is given in Figure 
235, in which the line A B is divided into inches and 
parts to represent the pitches; its total length repre- 
senting the coarsest pitch within the capacity of the 
scale; and the line B C (at a right-angle to A B) the 



3 
TO 


of the pitch, 


t'o 


CC (( 


tV 


(( (( 


.5 

TT 


(( (( 


6 

TT 


11 et 



jg5 MECHANICAL DRAWING SELF-TAUGHT. 

whole depth of the tooth for the coarsest pitch, beino' 
t'o of the lenorth of A B. 



2_0 — lbs per fnch Breadth of Face 




j Depth of Pitch Line 
• Thickness of Tooth 



_Wi_dth_of_Space 

Working Depth of Tooth j 



Whole Depth of Tooth 



Fig. 235. 

The other diag^onal lines are for the proportion of 
the dimensions marked on the fieure. Thus the 



DRAWING GEAR WHEELS. 



197 



depth of face, or distance from the pitch line to the 
extremity or tooth point for a 4 inch pitch, would 
be measured alone the line B C, from the verdcal line 
B to the first diaofonal. The thickness of the tooth 
would be for a 4 inch pitch along line B C from B to 
the second diagonal, and so on. For a 3 inch pitch 
the measurement would be taken along the horizontal 
line, starting from the 3 on the line A B, and so on. 
On the left of the diagram or scale is marked the tt)s. 
strain each pitch will safely transmit per inch width 
of wheel face, accordincr to Professor Marks. 




Fig. 236. 

The application of the scale is as follows: The pitch 
circles P P and P P', Figure 236, for the respective 
wheels, are drawn, and the height of the teeth is ob- 
tained from the scale and marked beyond the pitch 
circles, when circles Q and Q' may be drawn. Sim- 
ilarly, the depths of the teeth within the pitch circles are 
obtained from the scale or diagram and marked within 
the respective pitch circles, and circles R and R' are 
marked in. The pitch circles are divided off into as 
many points of equal division, as at a,b, c, d, e, etc., as 
the respective wheels are to have teeth, and the thick- 
ness of tooth having been obtained from the scale, this 



1^8 MECHANICAL DRAWING SELF-TAUGHT. 

thickness is marked from the points of division on the 
pitch circles, as at/ in the figure, and the tooth curves 
may then be drawn in. It may be observed, however, 
that the tooth thicknesses will not be strictly correct, 
because the scale gives the same chord pitch for the 
teeth on both wheels which will give different arc 
pitches to the teeth on the two wheels; whereas, it is 
the arc pitches, and not the chord pitches, that should 
be correct. This error obviously increases as there 
is a greater amount of difference between the two 
wheels. 

The curves given to the teeth in Figure 234 are 
not the proper ones to transmit uniform motion, but 
are curves merely used by draughtsmen to save the 
trouble of finding the true curves, which if it be re- 
quired, may be drawn with a very near approach to 
accuracy, as follows, which is a construction given by 
Rankine : 

Draw the rolling circle D, Figure 237, and draw A 
D, the line of centres. From the point of contact at 
C, mark on D, a point distant from C one-half the 
amount of the pitch, as at P, and draw the line P C of 
indefinite length beyond C. Draw the line P E passing 
through the line of centres at E, which is equidistant 
between C and A. Then increase the length of line 
P F to the right of C by an amount equal to the 
radius A C, and then diminish it to an amount equal 
to the radius E D, thus obtaining the point F, and the 
latter will be the location of centre for compasses to 
strike the face curve. 

Another method of finding the face curve, Avith 
compasses, is as follows: In Figure 238 let P P rep- 



DRAWING GEAR WHEELS. 



199 



resent the pitch circle of the wheel to be marked, and 
B C the path of the centre of the generating or de- 




scribing circle as it rolls outside of P P. Let the 
point B represent the centre of the grnerating circle 




when It Is In contact with the pitch circle at A. Then 
from B mark off, on B C, any number of equidistant 



]00 



MECHAXICAL DRAWING SELF-TAUGHT. 



points, as D, E, F, G, H, and from A mark on the 
pitch circle, with the same radius, an equal number of 
points of division, as i, 2, 3, 4, 5. With the com- 
passes set to the radius of the generating circle, that 
is, A B, from B, as a centre, mark the arc I, from D, 
the arc J, from E, the arc K, from F, and so on, mark- 
ing as many arcs as there are points of division on B 
C. With the compasses set to the radius of divisions 
I, 2, etc.," step off on arc M the five divisions, N, O, 
S, T, V, and at V will be a point on the epicycloidal 
curve. From point of division 4, step off on L four 




Fig. 239. 

points of division, as a, b, c, d ; and d will be another 
point on the epicycloidal curve. From point 3, set 
off three divisions, and so on, and through the points 
so obtained draw by hand, or with a scroll, the curve. 
Hypocycloids for the flanks of the teeth maybe traced 
in a similar manner. Thus in Figure 239, P P is the 
pitch circle, and B C the line of motion of the centre 
of the generating circle to be rolled within P P. From 
I to 6 are points of equal division on the pitch circle, 
and D to I are arc locations for the centre of the iren- 



DRAWING GEAR WHEELS. 20 1 

erating circle. Starting from A, which represents the 
location for the centre of the eeneratinof circle, the 
point of contact between the generating and base cir- 
cles will be at B. Then from i to 6 are points of 
equal division on the pitch circle, and from D to I are 
the corresponding locations' for the centres of the gen- 
erating circle. From these centres the arcs J, K, L, 
M, N, O, are struck. The six divisions on O, from a 
to y^ give atya point in the curve. Five divisions 
on N, four on M, and so on, give, respectively, points 
in the curve. 

There is this, however, to be noted concerning the 
construction of the last two figures. Since the circle 
described by the centre of the generating circle is 
of a different arc or curve to that of the pitch circle, 
the length of an arc having an equal radius on each 
will be different. The amount is so small as to be 
practically correct. The direction of the error is to 
give to the curves a less curvature, as though they 
had been produced by a generating circle of larger 
diameter. Suppose, for example, that the difference 
between the arc a, b, and its chord is .i, and that the 
difference between the arc 4, 5, and Its chord is .01, 
then the error in one step is .09, and, as the point/ 
is formed in five steps, it will contain this error multi- 
plied five times. Point d would contain it multiplied 
three times, because It has three steps, and so on. 

The error will increase in proportion as the diame- 
ter of the generating Is less than that of the pitch 
circle, and though in large wheels, working with large 
w^heels, so that the- difference between the radius of 
the generating circle and that of the smallest wheel is 



202 



MECHANJCAL DRAWING SELF-TAUGHT. 



not excessive, it is so small as to be practically inap- 
preciable, yet in small wheels, working with large 
ones, it may form a sensible error. 

For showing the dimensions through the arms and 






Fig. 240. 

hub, a sectional view of a section of the wheel may be 
given, as in Figure 240, which represents a section of 
a wheel, and a pinion, and on these tvvo views all the 
necessary dimensions may be marked. 




Fig. 240 




(Page 203.) 



DRAWING GEAR WHEELS. 203 

If it is desired to draw an edee view of a wheel 
(which the student will find excellent practice), the 
lines for the teeth may be projected from the teeth in 
the side view, as in Figure 240 a. Thus tooth E is 
projected by drawing lines from the corners A, B, C, 
in the side view across the face in the edge view, as 
at A, B, C in the latter view, and similar lines may be 
obtained in the same way for all the teeth. 

When the teeth of wheels are to be cut to form in 
a crear-cuttine machine, the thickness of the teeth is 
nearly equal to the thickness of the spaces, there being 
just sufficient difference to prevent the teeth of one 
wheel from becoming locked in the spaces of the other; 
but when the teeth are to be cast upon the wheel, the 
tooth thickness is made less than the width of the 
space to an amount that is usually a certain propor- 
tion of the pitch, and is termed the side clearance. 
In all wheels, whether with cut or cast teeth, there is 
given a certain amount of top and bottom clearance ; 
that is to say, the points of the teeth of one wheel do 
not reach to the bottom of the spaces in the other. 
Thus in the Pratt and Whitney system the top and 
bottom clearance is one-eighth ot the pitch, while in 
the Brown and Sharpe system for involute teeth the 
clearance is equal to one-tenth the thickness of the 
tooth. 

In drawing bevil gear wheels, the pitch line of each 
tooth on each wheel, and the surfaces of the points, as 
well as those at the bottom of the spaces, must all 
point to a centre, as E in Figure 241, which centre is 
where the axes of the shafts would meet. It is unne- 
cessary to mark in the correct curves for the teeth, 



204 



MECHANICAL DRAWING SELF-TAUGHT. 



for reasons already stated, with reference to the curves 
for a spur wheel. But if it is required to do so, the 
construction to find the curves is as shown in Figure 
242, in which let A A represent the axis of one shaft, 
and B that of the other of the pair of bevil wheels that 
are to work together, their axes meeting at W ; draw 
the line E at a right angle to A A, and representing 
the pitch circle diameter of one wheel, and draw F at 
a right angle to B, and representing the pitch circle of 
the other wheel ; draw the line G G, passing through 




the point W and the point T, where the pitch circles 
or lines E F meet, and G G will be the line of contact 
of the tooth of one wheel upon the tooth of the other 
wheel ; or in other words, the pitch line of the tooth. 
Draw lines, as H and I, representing the tooth 
breadth. From W, as a centre, draw on each side of 
G G dotted lines, as P, representing the height of the 
tooth above and below the pitch line G G. At a right 
angle to G G draw the line J K ; and from where this 
Hne meets B, as at Q, mark the arc a, which will repre- 
sent the pitch circle for tlic large diameter of the pinion 



DRAWING GEAR WHEELS. 



205 



D. [The smallest wheel of a pair of gears is termed 
the pinion.] Draw the arc b for the height, and circle c 
for the depth of the teeth, chus defining the height of 
the tooth at that end. Similarly from P, as a centre 
marie (for the large diameter of wheel C,) arcs g, h, 




Fig. 242. 



and i, arc g representing the pitch circle, t the height, 
and h the depth of the tooth. On these arcs draw 
the proper tooth curves in the same manner as for 
spur wheels; that is, obtain the curves by the construe- 



^q5 mechanical drawing self-taught. 

tion shown in Figures 237, or by those in Figures 238 
and 239. 

To obtain the arcs for the other end of the tooth, 
draw Hne M M parallel to line J K; set the compasses 
to the radius R L, and from P, as a centre, draw the 
pitch circle k. For the depth of the tooth draw the 
dotted line p, meeting the circle h and the point W. 
A similar line, from i to W, will give the height of the 
tooth at its inner end. Then the tooth curves may be 
drawn on these three arcs, k, /, m, in the same as if 
they were for a spur wheel. 

Similarly for the pitch circle of the inner and 
small end of the pinion teeth, set the compasses to 
radius S L, and from Q as a centre mark the pitch 
circle d. Outside of d mark e for the heicrht above 
pitch lines of the tooth, and inside of d mark the arc 
f for the depth below pitch line of the tooth at that 
end. The distance between the dotted lines as /, rep- 
resents the full height of the tooth ; hence h meets /, 
which is the root of the tooth on the laro^e wheel. To 
give clearance and prevent the tops of the teeth on 
one wheel from bearinof aorainst the bottoms of the 
spaces in the other wheel, the point of the pinion 
teeth is marked below ; thus arc b does not meet h or 
/, but is short to the amount of clearance. Having 
obtained the arcs d, e,f, the curves may be marked 
thereon as for a spur wheel. A tooth thus marked is 
shown at x, and from its curves between b and c, a 
template may be made for the large diameter or outer 
end of the jjinion tec th. Similarly for the wheel C 
the outer end curves arc marked on the arcs ^^, //, /', 
and those for the other end of the tooth are marked 
between the arcs /, m. 




(Page 207.) 



DRAWING GEAR WHEELS. 



■07 



Figure 243 represents a drawing of one-half of a 
bevil gear, and an edge view projected from the same. 
The point E corresponds to point E in Figure 241, or 
W in 242. The Hne F shows that the top surface of the 
teeth points to E. Line G shows that the pitch Hne 
of each tooth points to E, and Hnes H show that the 
bottom of the surface of a space also points to E. 
Line i shows that the sides of each tooth point to E. 
And it follows that the outer end of a tooth is both 
higher or deeper and also thicker than its inner end \ 




Fig. 244. 

thus J is thicker and deeper than end K of the tooth. 
Lines F G, representing the top and bottom of a tooth 
in Figure 243, obviously correspond to dotted lines/ 
in Figure 242. The outer and inner ends of the teeth 
in the edge view are projected from the outer and 
inner ends in the face view, as is shown by the dotted 
lines carried from tooth L in the face view, to tooth L 
in the edge view, and it is obvious from what has been 
said that in drawing the lines for the tooth in the edge 
view they will point to the centre E. 



208 



MECHANICAL DRAWING SELF-TAUGHT. 



To save work In drawing bevll gear wheels, they 
are sometimes drawn In section or In outHne only ; 
thus In Figure 244 Is shown a pair of bevll wheels 
shown in section, and In Figure 245 is a drawing of a 
part of an Ames lathe feed motion. BCD and E 
are spur gears, while G H and I are bevll gears, the 




fWk 77/////7Z7^7777^^ |^<v^ 




Q 
V 



£1 
Fig. 245. 



tt^xr^ 



cone surface on which the teeth lie being left blank, 
save at the edges where a tooth Is In each case drawn 
in. Wheel D is shown in section so as to show the 
means by which it may be moved out of gear with C 
and E. Small bevll gears may also be represented by 
simple line shading ; thus in Figure 247 the two 
bodies A and C would readily be understood to be a 
bevil gear and pinion. Similarly small spur wheels 




Fig. 249. (Page 209.) 



DRAWING GEAR WHEELS. 



209 



may be represented by simple circles in a side view 
and byline shading In an edge view; thus It would 
answer every practical purpose If such small wheels 




Fig, 246. 

as in Figures 246 and 247 at D, F, G, K, P, H, I and 
J, were drawn as shown. The pitch circles, how- 
ever, are usually drawn In red ink to distinguish 
them. 

— ^ 



/a= 



Fig. 247. 

In Figure 248 is an example in which part of the 
gear is shown with teeth in, and the remainder is Illus- 
trated by circles. 

In Figure 249 is a drawing of part of a Niles Tool 

Works horizontal boring mill. Figures 250 and 251 

are front views of the feed motions, y is a friction 

disk, and g a friction pinion, g' Is a rack, F is a feed- 

14 




210 



MECHANICAL DRA IVIXG SELF- TA UGHT. 



screw, / Is a bevel pinion, and q a bevel wheel ; i, m, 
c\ are gear wheels, and y a worm operating a worm- 
pinion and the gears shown. 

All these wheels and pinions are merely line-shaded 
in Figures 250 and 251 on account of their being too 
small to have the teeth drawn in. 

The construction of oval crearinor Is shown in 




Figures 252, 253, 254, 255, and 256. The pitch-circle 
is drawn by the construction for drawing an ellipse 
that was given with reference to Figure 81, but as 
that construction is by means of arcs of circles, and 
therefore not stricdy correct, Professor McCord, in an 
article on elliptical gearing, says, concerning it and 
the construction of oval gearing generally, as follows: 
"But these circular arcs maybe rectified and sub- 



DRAWING GEAR WHEELS. 



211 




Fig. 251. 



2X2 MECHANICAL DRAWING SELF-TAUGHT. 

divided with great facility and accuracy by a very 
simple process, which we take from Prof. Rankine's 
"Machinery and Mill Work," and is illustrated in Fig- 
ure 252. Let O B be tangent at O to the arc O D, 
of which C is the centre. Draw the chord D O, bisect 
it in E, and produce it to A, making O A=0 E; with 
centre A and radius A D describe an arc cutting the 
tangent in B ; then O B will be very nearly equal in 
lenp^th to the arc O D, which, however, should not 




Fig. 252. 

exceed about 60 degrees; if it be 60 degrees, the 
error is theoretically about ^J(t of the length of the arc, 
O B being so much too short; but this error varies with 
the fourth power of the angle subtended by the arc, 
so that for 30 degrees it is reduced to tV of that 
amount, that is, to ttIitt). Conversely, let O B be a tan- 
gent of given length; make OF=i^ O B; then with 
centre F and radius F B describe an arc cutting the 
circle O D G (tangent to O B at O) in the point D-; 
then O D will be approximately equal to O B, the 



DRAWING GEAR WHEELS. 



213 



error being the same as in the other construction and 
following the same law. 

The extreme simplicity of these two constructions 
and the facility with which they may be made with or- 



i, 




Fig. 253. 
dinary drawing instruments make them exceedingly 
convenient, and they should be more widely known 
than they are. Their application to the present 
problem is shown in Figure 253, which represents a 



214 



MECHANICAL DRAWING SELF-TAUGHT. 



quadrant of an ellipse, the approximate arcs C D^ 
E, E F, F A having been determined by trial and 
error. In order to space this off, for the positions of 
the teeth, a tangent is drawn at D, upon which is con- 
structed the rectification of D C, which is D G, and 
also that of D E in the opposite direction, that is, D 
H, by the process just explained. Then, drawing the 
tangent at F, we set off in the same manner F I=F E, 




and F K = F A, and then measuring H L == I K, we 
have finally G L, equal to the whole quadrant of the 
ellipse. 

Let it now be required to lay out twenty-four teeth 
upon this ellipse; that is, six in each quadrant; and 
for syrametry's sake we will suppose that the centre 
of one tooth is to be at A, and that of another at C, 



DRAWING GEAR WHEELS. 215 

Figure 253. We, therefore, divide LG into six equal 
parts at the points i, 2, 3, etc., which will be the 
centres of the teeth upon the rectified ellipse. It 
is practically necessary to make the spaces a little 
greater than the teeth ; but if the greatest attainable 
exactness in the operation of the wheels is aimed at, 
it is important to observe that backlash, in elliptical 
gearing, has an effect quite different from that result- 
ing in the case of circular wheels. When the pitch- 
curves are circles, they are always in contact ; and we 
may, if we choose, make the tooth only half the 
breadth of the space, so long as its outline is correct. 
When the motion of the driver is reversed, the fol- 
lower will stand still until the backlash is taken up, 
when the motion will go on with a perfectly constant 
velocity ratio as before. But in the case of two ellip- 
tical wheels, if the follower stand still while the driver 
moves, which must happen when the motion is re- 
versed if backlash exists, the pitch-curves are thrown 
out of contact, and, although the continuity of the 
motion will not be interrupted, the velocity ratio will he 
affected. If the motion is never to be reversed, the per- 
fect law of the velocity ratio due to the elliptical pitch- 
curve may be preserved by reducing the thickness of 
the tooth, not equally on each side, as is done in cir- 
cular wheels, but wholly on the sid-e not in action. 
But if the machine must be capable of acting indiffer- 
ently in both directions, the reduction must be made 
on both sides of the tooth: evidendy the action will be 
slightly impaired, for which reason the backlash should 
be reduced to a minimum. Precisely what is the 
minimum is not so easy to say, as it evidently depends 



2i5 MECHANICAL D RAWING SELF-TAUGHT. 

much upon the excellence of the tools and the skill of 
the workman. In many treatises on constructive 
mechanism it is variously stated that the backlash 
should be from one-fifteenth to one-eleventh of the 
pitch, which w^ould seem to be an ample allowance in 
reasonably good castings not intended to be finished, 
and quite excessive if the teeth are to be cut; nor is 
it very obvious that its amount should depend upon 
the pitch any more than upon the precession of the 
equinoxes. On paper, at any rate, we may reduce it 
to zero, and make the teeth and spaces equal in 
breadth, as showm in the figure, the teeth being indi- 
cated by the double lines. Those upon the portion 
L H are then laid off upon K I, after w^hich these di- 
visions are transferred to the ellipse by the second of 
Prof. Rankine's constructions, and we are then ready 
to draw the teeth. 

The outlines of these, as of any other teeth upon 
pitch-curves which roll together in the same plane, 
depend upon the general law that they must be such 
as can be marked out upon the planes of the curves, 
as they roll by a tracing-point, which is rigidly con- 
nected with and carried by a third line, moving in 
rolling contact wnth both the pitch-curves. And since 
under that condition the motion of this third line, rela- 
tively to each of the odiers, is the same as though it 
rolled along each of them separately while they re- 
mained fixed, the process of constructing the gener- 
ated curves becomes comparatively simple. For the 
describing Hne we naturally select a circle, which, in 
order to fulfil the condition, must be small enoueh to 
roll within the pitch ellipse; its diameter is determined 



DRAWING GEAR WHEELS. 



217 



by the consideration that if it be equal to A P, the 
radius of the arc A F, the flanks of the teeth in that 
region will be radial. We have, therefore, chosen a 
circle whose diameter, A B, is three-fourths of A P, 
as shown, so that the teeth, even at the ends of the 
wheels, will be broader at the base than on the pitch 
line. This circle ought strictly to roll upon the true 
elliptical curve ; and assuming, as usual, the tracing- 
point upon the circumference, the generated curves 
would vary slightly from true epicycloids, and no two 
of those used in the same quadrant of the ellipse 
w^ould be exactly alike. Were it possible to divide 
the ellipse accurately, there would be no difficulty in 
laying out these curves; but having substituted the 
circular arcs, we must now roll the generating circle 
upon these as bases, thus forming true epicycloidal 
teeth, of which those lying upon the same approxima- 
ting arc w^ill be exactly alike. Should the junction of 
two of these arcs fall within the breadth of a tooth, as 
at D, evidently both the face and the flank on one 
side of that tooth will be different from those on the 
other side; should the junction coincide with the edge 
of a tooth, which is very nearly the case at F, then the 
face on that side will be the epicycloid belonging to 
one of the arcs, its flank a hypocycloid belonging to 
the other; and it is possible that either the face or the 
flank on one side should be generated by the rolling 
of the describing circle partly on one arc, partly on 
the one adjacent, which, upon a large scale, and where 
the best results are aimed at, may make a sensible 
change in the form of the curve. 

The convenience of the constructions griven in Fie- 



2i8 MECHANICAL DRAWING SELF-TAUGHT. 

ure 252 is nowhere more apparent than in the draw- 
ing of the epicycloids, when, as in the case in hand- 
the base and generating circles may be of incommen- 
surable diameters ; for which reason we have, in Fig- 
ure 254, shown its application in connection with the 
most rapid and accurate mode yet known of describ- 
inor those curves. Let C be the centre of the base 

o 

circle ; B, that of the rolling one ; A, the point of con- 
tact. Divide the semi-circumference of B into six 
equal parts at i, 2, 3, etc. ; draw the common tangent 
at A, upon which rectify the arc A2 by process No. i ; 
then by process No. 2 set out an equal arc A 2 on the 
base circle, and stepping it off three times to the right 
and left, bisect these spaces, thus making subdivisions 
on the base circle equal in length to those on the roll- 
ing one. Take in succession as radii the chords Ai, 
A2, A3, etc., of the describing circle, and with centres 
I, 2, 3, etc., on the base circle, strike arcs either exter- 
nally or internally, as shown respectively on the right 
and left; the curve tangent to the external arcs is the 
epicycloid, that tangent to the internal ones the hypo- 
cycloid, forming the face and flank of a tooth for the 
base circle. 

In the diagram. Figure 253, we have shown a part 
of an ellipse whose length is ten inches, and breadth 
six, the figure being half size. In order to give an 
idea of the actual appearance of the combination when 
complete, we show in Figure 255 the pair in gear, on 
a -scale of three inches to the foot. The excessive 
eccentricity was selected merely for the purpose of 
illustration. Figure 255 will serv« also to call atten- 
tion to another serious circumstance, which is, that 



DRAWING GEAR WHEELS. 



219 



although the elHpses are ahke, the wheels are not ; 
nor can they be made so if there be an even number 
of teeth, for the obvious reason that a tooth upon one 
wheel must fit into a space on the other ; and since in 
the first wheel, Figure 255, we chose to place a tooth 
at the extremity of each axis, we must in the second 
one place there a space instead ; because at one time 




Fig. 255. 
the major axes must coincide ; at another, the minor 
axes, as in Figure 255. If, then, we use even num- 
bers, the distribution, and even the forms of the teeth, 
are not the same in the two wheels of the pair. ^ But 
this complication may be avoided by using an odd 
number of teeth, since, placing a tooth at one extrem- 
ity of the major axes, a space will come at the other. 



220 



MECHANICAL DRAWING SELF-TaUGHT. 



It is not, however, always necessary to cut teeth all 
round these wheels, as will be seen by an examination 
of Figure 256, C and D being the fixed centres of the 
two ellipses in contact at P. Now P must be on the 
line C D, whence, considering the free foci, we see 
that P B is equal to P C, and PA to P D ; and the 
common tangent at P makes equal angles with C P 
and P A, as is also with P B and P D ; therefore, C D 




Fig. 256. 

being a straight line, A B is also a straight line and 
equal to C D. If then the wheels be overhung, that 
is, fixed on the ends of the shafts outside the bearings, 
leaving the outer faces free, the moving foci may be 
connected by a rigid link A B, as shown. 

This link will then communicate the same motion 
that would result from the use of the complete ellip- 



DRAWING GEAR WHEELS. 221 

tical wheels, and we may therefore dispense with the 
most of the teeth, retaining only those near the ex- 
tremities of the major axes, which are necessary in 
order to assist and control the motion of the link 
at and near the dead-points. The arc of the pitch- 
curves through which the teeth must extend will vary 
with their eccentricity; but in many cases it would not 
be greater than that which in the approximation may 
be struck about one centre ; so that, in fact, it would 
not be necessary to go through the process of rectify- 
ing and subdividing the quarter of the ellipse at all, 
as in this case it can make no possible difference 
whether the spacing adopted for the teeth to be cut 
would "come out even" or not, if carried around the 
curve. By this expedient, then, we may save not only 
the trouble of drawing, but a great deal of labor in 
making, the tee thround the whole ellipse. We might 
even omit the intermediate portions of the pitch 
ellipses themselves; but as they move in rolling con- 
tact their retention can do no harm, and in one part 
of the movement will be beneficial, as they will do 
part of the work; for if, when turning, as shown by 
the arrows, we consider the wheel whose axis is D as 
the driver, it will be noted that its radius of contact, 
C P, is on the increase; and so long as this is the case 
the other wheel will be compelled to move by contact 
of the pitch lines, although the link be omitted. And 
even if teeth be cut all round the wheels, this link is 
a comparatively inexpensive and a useful addition to 
the combination, especially if the eccentricity be con- 
siderable. Of course the wheels shown in Figure 255 
might also have been made alike, by placing a tooth 



222 MECHANICAL DRAWING SELF-TAUGHT. 

at one end of the major axis and a space at the other, 
as above suororested. In reofard to the variation in the 
velocity ratio, it will be seen, by reference to Figure 
256, that if D be the axis of the driver, the follower 
will in the position there shown move faster, the ratio of 

P D 

the angular velocities being' ; if the driver turn 

P B 
uniformly, the velocity of the follower will diminish, 
until at the end of half a revolution, the velocity ratio 

PB 
will be ; in the other half of the revolution these 

PD 
changes will occur in a reverse order. But P D = L 
B; if then the centres B D are given in position, we 
know LP, the major axis; and in order to produce 
any assumed maximum or minimum velocity ratio, we 
have only to divide L P into segments whose ratio Is 
equal to that assumed value, which will give the foci 
of the ellipse, whence the minor axis may be found 
and the curve described. For instance, in Figure 255 
the velocity ratio being nine to one at the maximum, 
the major axis is divided into two parts, of which one 
is nine times as long as the other; in Figure 256 the 
ratio is as one to three, so that the major axis being 
divided into four parts, the distance A C between the 
foci is equal to two of them, and the distance of either 
focus from the nearest extremity of the major axis is 
equal to one, and from the more remote extremity is 
equal to three of these parts. 



CHAPTER XII. 

PLOTTING MECHANICAL MOTIONS. 

Let it be required to find how much motion an 
eccentric will give to its rod, the distance from the 
centre of its bore to the centre of the circumference, 
which is called the throw, being the distance from A 



to B in Fi 



gure 257. 



Now as the eccentric is moved 



/^^ 




around by the shaft, it is evident that the axis of its 
motion will be the axis A of the shaft. Then from A 
as a centre, and with radius from A to C, we draw the 
dotted circle D, and from E to F will be the amount 
of motion of the rod in the direction of the arrow. 

(223) 



224 



MECHANICAL DRAWIXG SELF-TAUGHT. 



This becomes obvious if we suppose a lead pencil 
to be placed against the eccentric at E, and suppose 
the eccentric to make half a revolution, whereupon 
the pencil will be pushed out to F. If now we measure 
the distance from E to F, we shall find it is just twice 
that from A to B. We may find the amount of motion, 
however, in another way, as by striking the dotted 
half circle G, showing the path of motion of B, the 
diameter of this path of motion being the amount of 
lateral motion given to the rod. 

In Fig'.re 258 is a two arm lever fast upon the 




same axis or shaft, and it is required to find how much 
a given amount of motion of the long arm will move 
the short one. Suppose the distance the long arm 
moves is to A. Then draw the line B from A to the 
axis of the shaft, and the line C the centre line of the 
long arm. From the axis of the shaft as a centre, 
draw the circle D, passing through the eye or centre 
E of the short arm. Take the radius from F to G, 
and from E as a centre mark it on D as at H, and H 
is where E will be when the long arm moves to A. 



PLOTTING MECHANICAL MOTIONS. 22$ 

We have here simply decreased the motion in the 
same proportion as one arm is shorter than the other. 
The principle involved is to take the motion of both 
arms at an equal .distance from their axis of motion, 
which is the axis of the shaft S. 

In Figure 259 we have a case in which the end of a 




Fig. 259. 

lever acts directly upon a shoe. Now let it be re- 
quired to find how much a given motion of the lever 
will cause the shoe to slide along the line;t-; the point 
H is here found precisely as before, and from it as a 
centre, the dotted circle equal in diameter to the small 
circle at E is drawn from the perimeter of the dotted 
circle, a dotted line is carried up and another is car- 
ried up from the face of the shoe. The distance K 
between these dotted lines is the amount of motion of 
the shoe. 

In Figure 260 we have the same conditions as in Fig- 
ure 259, but the short arm has a roller acting against a 
larger roller R. The point H is found as before. The 
amount of motion of R is the distance of K from J : 
hence we may transfer this distance from the centre of 
15 



22b 



MECHANICAL DRAWING SELF-TAUGHT. 



R, producing the point P, from which the new position 

may be marked by a dotted circle as shown. 




Fig. 260. 

In Figure 261 a Hnk is introduced in place of the rol- 
ler, and it is required to find the amount of motion of 
rod R. The point H is found as before, and then the 
length from centre to centre of link L is found, and 
with this radius and from H as a centre the arc P 




Fig. 261. 

is drawn, and where P intersects the centre line J of 
R is the new position for the eye or centre O of R. 

In Figure 262 we have a case of a similar lever actua- 
ting a plunger in a vertical line, it being required to find 
how much a given amount of motion of the long arm will 
actuate the plunger. Suppose the long arm to n.ove 



PLOTTING MECHANICAL MOTIONS. 22/ 

to A, then draw the lines B C and the circle D. Take 
the radius or distance F, G, and from E mark on D 
the arc H. Mark the centre line J of the rod. Now 
take the length from E to I of the link, and from H as 




Fig. 262. 

a centre mark arc K, and at the intersection of K 
with J is where the eye I will be when the long arm 
has moved to A. 

In Figure 263 are two levers upon their axles or 
shafts S and S' ; arm A is connected by a link to arm 
B, and arm C is connected direct to a rod R. It is re- 
quired to find the position of centre G of the rod eye 
when D is in position E, and when it is also in position 
F. Now the points E and F are, of course, on an arc 
struck from the axis S, and it is obvious that in what- 
ever position the centre H may be it will be some- 
where on the arc I, I, which is struck from the centre 
S'. Now suppose that D moves to E, and if we take 



228 MECHANICAL DRAWING SELF-TAUGHT. 

the radius D, H, and from E mark it upon the arc I as 
at V, then H will obviously be the new position of H. 
To find the new position of G we first strike the arc 
J, J, because in every position of G it will be some- 
where on the arc J, J. To find where that will be 
when H is at V, take the radius H, G, and from V as 




Fig. 263. 

a centre mark it on J, J, as at K, which Is the position 
of G when D is at E and H is at V. For the posi- 
tions when D Is at F we repeat the process, taking the 
radius D, H, and from F marking P, and with the 
radius H, G, and from P as a centre marking Q ; then 
P Is the new position for H, and Q is that for G. 

In Figure 264 a lever arm A and cam C are in one 
piece on a shaft. S Is a shoe sliding on the line x, 
and held against the cam face by the rod R; it is 
required to find the position of the face of the shoe 
against the cam when the end of the arm is at D. 



PLOTTING MECHANICAL MOTIONS. 



22g 



Draw line E from D to the axis of the shaft and 
line F. From the shaft axis as a centre draw circle 
W; draw line J parallel to x. Take the radius G H, 
and from K as a centre mark point P on W ; draw 
line Q from the shaft axis through P, and mark point 
T. From the shaft axis as a centre draw from T an 
arc, cutting J at V, and V is the point where the face 
of the shoe and the face of the cam will touch when 
the arm stands at D. 

Let it be required to find the amount of motion im- 
parted in a straight line to a rod attached to an eccen- 




p\ 






I 




R 


.-p- 


\ 


\ 






/ 




X 



Fig. 264. 

trie strap, and the following construction may be used. 
In Figure 265 let A represent the centre of the shaft, 
and, therefore, the axis about which the eccentric re- 
volves. Let B represent the centre of the eccentric, 
and let it be required to find in what position on the 
line of motion x, the centre C of the rod eye will be 
when the centre B of the eccentric has moved to E. 
Now since A is the axis, the centre B of the eccentric 
must rotate about it as denoted by the circle D, and 
all that is necessary to find the position of C for any 
position of eccentric is to mark the position of B on 
circle D, as at E, and from that position, as from E, 



2.^0 



MECHANICAL DRAWING SELF-TAUGHT. 



as a centre, and with the length of the rod as a radius, 
mark the new position of C on the Hne x of its mo- 
tion. With the centre of the eccentric at B, the line 
Q, representing the faces of the straps, will stand at a 
right angle to the line of motion, and the length of the 
rod is from B to C ; when the eccentric centre moves 
to E, the centre line of the rod will be moved to posi- 
tion P, the line Q will have assumed position R, and 
point C will have moved from its position in the draw- 




Fig. 265. 

ing to G on line x. If the eccentric centre be sup- 
posed to move on to F, the point C will move to H, 
the radii B C, E G, and F H all being equal in length. 
Now when the eccentric centre is at E it will have 
moved one-quarter of a revolution, and yet the point C 
will only have moved to G, which is not central be- 
tween C and H, as is denoted by the dotted half 
circle I. 

On the other hand, while the eccentric centre is 



PLOTTING MECHAXICAL MOTIONS. 



23i 



moving from E to F, which is but one-quarter of a 
revolution, the rod end will move from G to H. This 
occurs because the rod not only moves endwise, but 
the end connected to the eccentric strap moves to- 
wards and away from the line x. This is shown in 
the figure, the rod centre line being marked in full line 
from B to x. And when B has moved to E, the rod 
centre line is marked by dotted line E, so that it has 
moved away from the line of motion B x. In Figure 
266 the eccentric centre is shown to stand at an anole 




J K G 



Fig. 266. 



of 45 degrees from line q, which is at a right angle 
to the line of motion x x, and the position of the rod 
end is shown at C, J and H representing the extremes 
of motion, and G the centre of the motion. 

If now we suppose the eccentric centre to stand at 
T, which Is also an angle of 45 degrees to q, then the 
rod end will stand at K, which is further away from G 
than C is; hence we find that on account of the move- 



2^2 MECHANICAL DRAWING SELF-TAUGHT. 

ment of the rod out of the straight end motion, the 
iiiotion of the rod end becomes irregular in proportion 
to that of the eccentric, whose action in moving the 
eye C of the rod in a straight hne is increased (by the 
rod) while it is moving through the half rotation de- 
noted by V in figure, and diminished during the other 
half rotation. 

In many cases, as, for example, on die river steam- 
boats in the Western and Southern States, cams are 
employed instead of eccentrics, and the principles in- 
volved in drawine or marking out such cams are eiven 
in the following remarks, which contain the substance 
of a paper read by Lewis Johnson before the American 
Society of Mechanical Engineers. In Figure 267 is a 
side view of a pair of cams; one, C, being a full stroke 
cam for operating the valve that admits steam to the 
engine cylinder ; and the other, D, being a cam to cut 
off the steam supply at the required point in the engine 
stroke. The positions of these cams with relation to 
the position of the crank-pin need not be commented 
upon here, more than to remark that obviously the 
cam C must operate to open the steam inlet valve in 
advance of cam D, which operates to close it and 
cause the steam to act expansively in the cylinder, and 
that the angle of the throw line of the cut-off valve D 
to the other cam or to the crank-pin varies according 
as it is required to cut off the steam either earlier or 
later in the stroke. 

The cam yoke is composed of two halves, Y and 
Y', bolted together by bolts B, which have a collar at 
o\\<i end and two nuts at the other end, the inner nuts 
N N enabling the letting together of the two halves 



PL O TTING ME CHA NIC A L MO 1 1 QMS. 



233 




Fig. 267. 



2 -.A MECHANICAL DRAWING SELF-TAUGHT. 

oi the yoke to take up the wear. It is obvious that 
as the shaft revolves and carries the cam with it, it 
will, by reason of its shape, move the yoke back and 
forth; thus, in the position of the parts shown in Figure 
267, the direction of rotation being denoted by the 
arrow, cam C will, as it rotates, move the yoke to the 
left, and this motion will occur from the time corner a 
of the cam meets the face of Y' until corner b has 
passed the centre line d. Now since that part of the 
circumference lying between points a and b of the 
cam is an arc of a circle, of which the axis of the shaft 
is the centre, the yoke will remain at rest until such 
time as b has passed line ^and corner a meets the jaw 
Y of the yoke ; hence the period of rest is determined 
by the amount of circumference that is made concen- 
tric to the shaft ; or, in other words, is determined by 
the distance between a and b. 

The object of using a cam instead of an eccentric is 
to enable the opening of the valves abruptly at the 
beginning of the piston stroke, maintaining a uniform 
steam-port opening during nearly the entire length of 
stroke, and as abruptly closing the valves at the termi- 
nation of the stroke. 

Figure 268 is a top view of the mechanism in Figure 
267 ; and Figure 269 shows an end view of the yoke. 
At B, in Figure 268, is shown a guide through which 
the yoke-stem passes so as to be guided to move in a 
straight line, there being a guide of this kind on each 
side of the yoke. 

The two cams are bolted to a collar that is secured 
to the crank-shaft, and are made in halves, as shown 
in the figures and also in Figures 270 and 271, which 



PLOTTING MECHANICAL MOTIONS. 235 

represent cams removed from the other mechanism. 




Fig. 268. 
To enable a certain amount of adjustment of the cams 



136 



MECHANICAL DRAWING SELF-TAUGHT. 



Upon the collar, the bolts which hold them to the collar 
fit closely in the holes in the collar, but the cams are 
provided with oblong bolt holes as shown, so that the 
position of either cam, either with relation to the other 
cam or with relation to the crank-pin, can be adjusted 




Scale r^^=l foot 
Fig. 269. 
to the extent permitted by the length of the oblong 
holes. 

The crank is assumed in the ficrures to be on its 
dead centre nearest to the engine cylinder, and to re- 
volve in the direction of the arrows. The cams are 



PLOTTING MECHANICAL MOTIONS. 



m 



SO arranged that their plain unflanged surfaces bolt 
against the collar. 

The method of drawing or marking out a full stroke 
cam, such as C in Figure 267, is illustrated in Figure 
572, in which the dimensions are assumed to be as 
follows : 

Diameter of crank shaft, 7^ inches; travel of cam, 
3 inches; width of yoke, 18 inches. 




Scale 1^ = ] To'jt 
Fig. 270. 



2^ 



The circumference of the cam is composed of four 
n\rved lines, P, F, K i, and K 2. The position of the 
centre of the crank shaft in this irregularly curved 
body is at X. The arcs K i and K 2 differ in radius, 
but are drawn from the same point, X, and hence are 
concentric with the crank shaft. 

The arcs P, P', are of like radius, but are drawn from 
the opposite points S, S, shown at the intersection of 



238 



MECHANICAL DRAWING SELF-TAUGHT, 




Scale l^—l foot 



PLOTTING MECHANICAL MOTIONS. 



239 



the arcs P, P', with the arc K i. Thus arcs P, P', are 
eccentric to the crank shaft. 

To draw the cam place one point of the dividers at 
X, which is the centre of the crank shaft, and draw 
the circle E equal to width of yoke, 18 inches. 
Through this centre X, draw the two right lines A 
and B. On the line B, at the intersection of the 
curved line E, draw the two vertical lines A i, A i. 
With a radius of 10^ inches, and with one point of 

5^. 18^ 




Fig. 273. 



the dividers at X, draw the arc K i. With a radius 
of 71^ inches, and one point of the dividers at X, 
draw the arc K 2. With a radius of 18 inches, and 
one point of the dividers at the intersection of the arc 
E, with the vertical line A i at S, draw the arc P opposite 
to S, and let it merge or lose itself in the curved line 
K 2. Draw the other curved line P' from the other 
point S, and we have a full stroke cam of the dimen- 



240 



MECHANICAL DRAWING SELF-TAUGHT. 



slons required, and which is represented in Figure 273, 
removed from the Hnes used in constructing it. 

The engravings from and including Figure 274 
illustrate the lines embracing cut-off cams of varying 




1 lo 5 



\A 

Scalp l'=l foot 
Fig. 274. 



limits of cut-off, but all of like travel and dimensions, 
which are the same as those given for the full stroke 
cam in Figure 272. 



PLOTTING MECHANICAL MOTIONS. 



241 



In drawing cut-off cams, the stroke of the engine 
plays a part in determining their conformation, and in 
the examples shown this is assumed to be 4 feet. 
Figure 274 illustrates the manner of finding essential 
points in drawing or marking out cut-off cams. With 
X as a centre, and a radius of 2 feet, draw the circle 
E I, showing the path of the crank-pin in making a 





/ 


<^ 


::::5 




,E 






— 7 






\ 


1 






X 


k) 


Y « 


J 


\\ 










Le, 


V" 


^ 


x^ 






y^ 






\ 






A 


Scale l4'„l 



Fig. 275 

revolution. This circle has a 
to the stroke of the eneine. 
line B, passing through the 
Within the limits of circle E 
eight equal parts, as at i, 2, 3 
tical lines, i, 2, 3, 4, etc., until 
circle E i. 

With X as a centre, draw 
16 



diameter of 4 feet, equal 
Draw the horizontal 
centre of circle E t, 
I, subdivide line B into 
, 4, etc. Draw the ver- 
they each intersect the 



the circle E. 



having a 



242 



MECHANICAL DRAWING SELF-TAUGHT. 



diameter of iS inches, equal to the space in the yoke 
embracinor the cam. 

From the centre X draw the series of radial lines 
through the points of intersection of the vertical lines 
I, 2, 3, 4, etc., from the circle E i, and terminating at 







Fig. 276. 

X. We will now proceed to utilize the scale afforded 
by Figure 274, in laying off the cut-off cam shown in 
Figure 276, of half stroke limit. 

With X as a centre, draw the circle E, Figure 275, 
having a diameter of 18 inches. Bisect this circle 
with the straight lines A and B, which bear the same 



PLOTTING MECHANICAL MOTIONS. 



243 



relation to their enclosing circle that the lines A, B, do 
to the circle E in Figure 274. 

It will be observed, in Figure 274, that the vertical 
line A is (at the top half ) also No. 4, representing f, or 
half of the stroke. With a radius of 1 8 inches, and 
one point of the dividers placed at V, which is at the 
intersection of the circle E with the horizontal line B 




Scale 1^=1 foot 



Fig. 277. 

in Figure 275, draw the arc P. With the same radius 
and with one compass point rested at V', draw the arc 
P'; then two arcs, P and P', intersecting at the point S. 
With the same radius and one point of the com- 
passes at S, draw the arc H H. The arcs K i and K 
2 are drawn from the centre X, with a radius of lo^^ 
for K I and 7J^ inches for K 2, and only serve m a 



244 



MECHANICAL DRAWING SELF-TAUGHT, 



half stroke cam to intersect the curved lines already 
drawn, as shown in Figure 275. In practice, the sharp 
corner at S would be objectionable, owing to rapid 
wear at this point ; and hence a modification of the 
dimensions for this half stroke cam would be required 
to obtain a larger wearing surface at the point S, but 




Fig. 278. 

the cam of this limit (3^ stroke) is correctly drawn 
by the process described with reference to Figure 275, 
the outline of the cam so constructed being- shown in 
Figure 276. 

In Figure 278 is shown a cam designed to cut off 
the steam at five-eighths of the piston stroke, the con- 



PLOTTING MECHANICAL MOTIONS. 245 

struction lines being given in Figure 277, for which draw 
circle E and straight lines A and B, as in the preceding 
example. By reference to Figure 274 it will be ob- 
served that the diagonal line drawn through circle E at 
5 is drawn from the straight line marked 5, which inter- 
sects circle E i, and as this straight line 5 represents 
rive-eighths of the stroke laid off on line B, it deter- 




Fig. 279. 

mines the limit of cut-off on the five-eighths cam in 
Figure 277. 

Turning then to Figure 274, take on circle E the 
radius from radial line 4 to radial line 5, and mark 
it in Figure 277 from the vertical line producing V'. 

Now, with a radius of 18 inches, and one point of 
the dividers fixed at point V, forming the intersection 
of the circle E with the horizontal Ijne B, draw the arc 



246 



MECHANICAL DRAWING SELF-TAUGHT. 



P. With the same radius, and one point of the dividers 
fixed at point V', draw the opposite arc P'. With a 
radius of 10^ inches from the centre X, draw the arc 
K I, intersecting lines P P', at S S. With a radius of 
7^ inches, draw the curved Hne K 2, opposite to 
curved line K i. Now, with a radius of 18 inches, 
and one point of the dividers fixed alternately at S S, 



y B 




Scale l-i=l foot 



Fig. 280. 



draw the arcs H, H, from their intersection with the 
circle E, until they merge into the curved line K 2. 
These curved lines embrace a cut-off cam of five- 
eighths limit, shown complete in Figure 278. 

From the Instructions already given It should be easy 
to understand that the three-fourths and seven-eighths 
cams, shown in Figures 279, 280, 281 and 282, are 



PLOTTING MECHANICAL MOTIONS. 



247 



drawn by taking the points of their cut-off from the 
same scale shown in Figure 274, at the diagonal points 
6 and 7, intersecting circle E in that figure ; and cut-off 
cams of intermediate limit of cut-off can be drawn by 
further subdividing the stroke Hne. B, in Figure 274, 
into the required limits. 

Cut-off cams of any limit are necessarily Imperfect 
in their operations as to uniformity of cut-off from 




Fig. 281. 

opposite ends of the slides, not from any defect in the 
rule for laying them off, but from the well-known fact 
of the crank pin travelling a greater distance, while 
driven by the piston from the centre of the cylinder, 
through Its curved path from the cylinder, over its 
centre, and back to the centre of the cylinder, than in 
accomplishing the remaining distance of its path in 
making a complete revolution ; and, although the sub- 



248 MECHANICAL DRAWING SELF-TAUGHT, 

divisions of eighths of the stroke Hne B, in Figure 
274, does not truly represent a Hke division of the 
piston stroke, owing to deviation, caused by inclination 
of the connecting rod in traversing from the centres 
to half stroke, still it v^ill be found that laying off a 
cut-off cam by this rule is more nearly correct than 
if the divisions on stroke line B were made to cor- 




— Ifoot 

Fig. 282. 

respond exactly with a subdivision of piston stroke 
mto eighths. 

The cut-off in cams laid off by the rules herein de- 
scribed is c^reater in travelllncr from one side of the 
slides than in travelling from the opposite end, one 
cut-off being more than the actual cut-off of piston 
stroke, and the other less ; and in practical use, owing 
to play or lost motion in the connections from cam to 



PLOTTING MECHANICAL MOTIONS. 



249 



valve, the actual cut-off is less than the theoretical ; 
hence cut-off cams are usually laid off to compensate 
for lost motion ; that is, laid off with more limit ; for 




Fig. 283. 

instance, a five-eighths cam would be laid off to cut-off 
at eleven-sixteenths instead of five-eighths. 

Figure 283 represents the motion a crank, C, im- 
parts to a connecting rod, represented by the thick 



2-0 MECHANICAL DRAWING SELF-TAUGHT. 

line R, whose end, B, is supposed to be guided to move 
in a straight Hne. The circle H represents the path 
of the crank-pin, and dots i, 2, 3, etc., are 24 dif- 
ferent crank-pin positions equidistant on the circle of 
crank-pin revolution. Suppose the crank-pin to have 
moved to position i,and with the compasses set to the 
length of the rod R, we set one point on the centre of 
position I, and mark on the line of motion m the line 
a, which will be the position rod end B will have moved 
to. Suppose next that the crank-pin has moved into 
position 2, and with the compass point on the centre 
of 2 we mark line 2, showing that while the crank-pin 
moved from i to 2, the rod end moved from a to b ; by 
continuing this process we are enabled to discern the 
motion for the whole of the stroke. The backward 
stroke will be the same, for corresponding crank-pin 
positions, for both strokes ; thus, when the rod end is 
at 7 the crank-pin may be at 7 or at 17. This fact 
enables us to find the positions for the positions later 
than 6, on the other side of the circle, as at 17, 16, 15, 
etc., which keeps the engraving clear. 

In Figure 284 a pinion, P, drives a gear-wheel, D, 
on which there is a pin driving the sliding die A in the 
link L, which is pivoted at C, and connected at its upper 
end to a rod, R. which is connected to a bolt, B, fast to 
a slide, S. It is required to find the motion of S, it 
moving in a straight line, dotted circle H' representing 
the path of the pin in the sliding die A, arc H repre- 
senting the line of motion of the upper end of link L, 
and lines N, O, its centre line at the extreme ends of 
its vibrating motion. In Figure 285 the letters of ref- 
erence refer to the same parts as those in Figure 284. 



PLOTTING MECHANICAL MOTIONS. 



251 



We divide the circle H' of pin motion into 24 equi- 
distant parts marked by dots, and through these we 




Fig. 284. 

draw lines radiating from centre, C, and cutting arc 
H, obtaining on the arc H the various positions for 
end Z of rod R, these positions being marked respec- 



252 



MECHANICAL DRAWING SELF-TAUGHT. 



tively I, 2, 3, 4, etc., up to 24. With a pair of com- 
passes set to the length of rod R from i on H. as a 
centre, we mark on the line of motion of the slide, line 
a, which shows where the other end of rod R will be 
(or in other words, it shows the position of bolt B in 
Figure 284), when the centre of A, Figure 284, is in 
position I, Figure 285. 

From 2 on arc H, we mark with the compasses line 
b on line M, showing that while the pin moved from i 
to 2, the rod R would move slide S, Figure 284, from 



Faruard Stroke 



ab c S e f g 

Mini I 1 -^ 1 



k I mnoj} _ 

I I I I iM 



Backward Stroke o\ 




Fig. 285. 

a to 6, in Figure 285. From 3 we mark c, and so on, 
all these marks being above the horizontal line M, 
representing the line of motion, and being for the for- 
ward stroke. For the backward stroke we draw the 
dotted line from position 17 up to arc H, and with the 
compasses at 17 mark a line beneath the line M of 
motion, pursuing the same course for all the other 
pin motions, as 18, 19, etc., until the pin arrives again 
at position 24, and the link at O, and has made a full 



PLOTTING MECHANICAL MOTIONS. 



253 



revolution, and we shall have the motion of the forward 
stroke above and that of the backward one below the 
line of motion of the slide, and may compare the two. 




Fig. 286. 

Figures 286 and 287 represent the Whitwortai quick 
return motion that is employed in many machines. F 
represents a frame supporting a fixed journal, B, on 



254 



MECHANICAL DRAWING SELF-TAUGHT. 



which revolves a gear-wheel, G, operated by a pinion, 
P. At A is an arm having journal bearing in B at C. 
This arm is driven by a pin, D, fast in the gear, G ; 
hence as the gear revolves, pin D moves A around on 
C as a centre of motion. A is provided with a slot 
carrying a pin, X, on which is pivoted the rod, R. 
The motion of end N of the rod R being in a straight 
line, M, it is required to find the positions of N during 
twenty-four periods in one revolution of G. In Figure 
288 let H' represent the path of motion of the driving 




Fig. 287. 

pin D, about the centre of B, and H the path of mo- 
tion of X about the centre C ; these two centres cor- 
responding to the centres of B and C respectively, in 
Figure 287. Let the line M correspond to the line 
of motion M in Figure 286. Now since it is the pin 
D, Figure 287, that drives, and since its speed of rev- 
olution is uniform, we divide its circle of motion H' into 
twenty-four equal divisions, and by drawing lines radi- 
ating from centre C,and passing through the lines of dl- 



PLOTTING MECHANICAL MOTIONS. 



255 



Vision on H' we get on circle H twenty-four positions for 
the pin X in Figure 286. Then setting the compasses 
to the length of the rod (R, Figure 286), we mark from 




•^ 



Fig. 288. 

position I on circle H as a centre line, a; from position 
2 on H we mark line b, and so on for the whole twenty- 
four positions on circle H, obtaining from a to n for the 



2^5 MECHANICAL DRAWING SELF-TAUGHT. 

forward, and from n \.o y for the motion during the 
backward stroke. Suppose now that the mechanism 
remaining precisely the same as before, the line M of 
motion be in a line with the centres C, B, instead of at 




Fig. 289. 



a right angle to it, as it is m Figure 2S6, and the motion 
under this new condition will be as in Figure 289; the 
process for finding the amount of motion along M 
from the motion around H being precisely as before. 



PLOTTIXG MECHAXICAL MOTIONS. 



257 



In Figure 290 is shown a cutter-head for a wood 




Fi 



z. 290. 



moulding machine, and it is required to find what 
17 



258 



:ECL'AXICAL DRA IVJXG SELb- lA i GJiT. 



shape the cutting edge of the cutter must be to form 
a moulclincx such as is shown in the end view of the 
mouldincr in the fiorure. Now the line A A beinor at 

o o o 

a rieht anole to the hne of motion of the moulding as 
it is passed beneath the revolving cutter, or, what is 
the same thing, at a right angle to the face of the 
table on which the moulding is moved, it is obvious 
that the highest point C of the moulding will be cut to 
shape by the point C of the cutter ; and that since the 
line of motion of the end of the cutter is the arc D, 
the lowest part of the cutter action upon the moulding 
will be at point E. It will also be obvious that as the 
cutter edge passes, at each point, its length across the 
line A A, it forms the moulding to shape, while all the 
cutting action that occurs on either side of that line is 
serving simply to remove material. All that we have 
to consider, therefore, is the action on line A A. 

It may be observed also that the highest point C of 
the cutter edge must not be less than y^ inch from the 
corner of the cutter head, which gives room for the 
nut N (that holds the cutter to the head) to pass over 
the top of the moulding in a 2j^ inch head. In pro- 
portion as the heads are made larger, however, less 
clearance is necessary for the nut, as is shown in Figure 
291, the cutter edge extending to C, and therefore 
nearly up to the corner of the head. Its path of mo- 
tion at C is shown by dotted arc B, which it will be 
observed amply clears the nut N. In practice, how- 
ever, point C is not in any size of cutter-head placed 
nearer than ^ inch from corner X of the cutter-head. 

To find the length of the cutter edge necessary to 
produce a given depth of moulding, we may draw a 



PLOTTING MECHANICAL MOTIONS. 



259 



Circles, Figure 292, equal in diameter to the size of 
the cutter head to be used, and Hne A A. The 
highest point of cutting edge being at e, and the 
lowest at g, then circles d and/ represent the line of 
motion of these two points; and if we mark the cutter 
in, the necessary length of cutting edge on the cutter 
is obviously from a to b. 



1 ' 




J^ 


^'^ 


E-^ 





V 



/ 



/ 



y 



y 



/ 




Now the necessary 
for any given mould 
curves for the edge 
pose the moulding is 
view in Figure 290. 
of course equal the 
length ^or depth of 



Fig. 291. 

depth of cutter edge being found 
ing, or part of a moulding, the 
may be found as follows : Sup- 
to be half round, as in the end 
The width of the cutter must 
width of the moulding, and the 
cutting edge required may be 



26o 



MECHANICAL DRAWING SELF-TAUGHT, 



found from the construction shown in Figure 292; 
hence all that remains is to find the curve for the cutting 
edge. In Figure 293, let A A represent the centre 
of the cutter width, its sides being F F', and its end B B. 
From centre C draw circle D, the upper half of which 
will serve to represent the moulding. Mark on A the 
length or depth the cutting edge requires to be, ascer* 
taining the same from the construction shown in Figure 




292, and mark it as from C to K'. Then draw line 
E E, passing through point K. Draw line G, standing 
at the same angle to A A as the face h b, Figure 292, 
of the cutter does to the line A A, and draw line H 
H, parallel to G. From any point on G, as at I, with 
radius J, draw a quarter of a circle, as K. Mark off 
this quarter circle into equal points of division, as by 
I, 2, 3, e^., and from these points of division draw 



PLOTTING MECHANICAL MOTIONS. 



261 




Fig. 293. 



262 



MECHANICAL DRAWING SELF-TAUGHT. 



lines, as a, b, c, etc. ; and from these lines draw hor- 
izontal lines d, e,f, etc. Now divide the lower half of 
circle D into twice as many equal divisions as quarter 
circle K is divided into, and from these points of di- 
vision draw perpendiculars g, k, i, etc. And where 
these perpendiculars cross the horizontal lines, as d, 
will be points through which the curve may be drawn, 
three of such points being marked by dots at/, q, ^. 




Molding 

Fig. 294. 

If the student will, after having drawn the curve by 
this construction, draw it by the construction that was 
explained in connection with Figure 79, he will find 
the two methods give so nearly identical curves, that 
the latter and more simple method may be used 
without sensible error. 

When the curves of the moulding are not arcs of 
circles they may be marked as follows; 



PLOTTING MECHANICAL MOTIONS. 263 

Take the drawing of the moulding and divide each 
member or step of it by equidistant Hnes, as a, b, c, d, e, 
f,g, in Figure 294; above the moulding draw lines 
representing the cutter, and having found the depth 
of cutting edge for each member by the construction 
shown in Figure 292, finding a separate line, a b, for 
each member of the moulding, transfer the depths so 
found to the face of the cutter; divide the depth of 
each member of the cutter Into as many equal divisions 
as the corresponding member of the moulding is 
divided into, as by lines h, i,j\ k, /, in, n. Then draw 
vertical lines, as o, p, q, r, etc.; and where these lines 
meet the respective lines h, i,j\ etc., are points in the 
curve, such points being marked on the cutter by dovi, 



CHAPTER XIII. 

MECHANICAL DRAWINGS FROM WHICH ENGRAVINGS 
ARE TO BE MADE. 

The mechanical drawino^s from which enorravinos 
are to be made are drawn to suit the particular proc- 
ess by means of which the engraving is to be pro- 
duced. The highly shaded and finished perspective 
drawinors that are found in the cataloorues of enorine 
and machine manufacturers are made by men who may 
be termed the artists of mechanical drawing. These 
men are indeed not mechanical draftsmen in the 
ordinary sense of the term ; since they do not make 
a study of the questions that arise in the designing 
of machinery or of the construction of work-shop 
drawings, but rather turn their attention to the pro- 
duction of pictures that shall be attractive to the eye, 
while giving a general idea of the construction of the 
machine as a whole. 

Drawings that are shaded by lines and not by tints, 
may be engraved by three methods : first, by photo- 
engraving, in which process every line appears in the 
engraving precisely as it appears in the drawing. 

For this kind of engraving the drawing may be 
made of any convenient size that is larger than the 
size of engraving to be produced, the reduction of size 
being produced in the photographing process. Draw- 
ings for photo-engraving require to have the lines jet 
(264) 



EXAMPLES IN LIAE-SHADIXG. 265 

black, and it is to be remembered that if red centre- 
lines are marked on the drawing, they will be produced 
as ordinary black lines in the engraving. 

The shading on a drawing to be photo-engraved must 
be produced by lines, and not by tints, for tints, whether 
of black or of colors, will not photo-engrave properly. 

It is generally preferred to make the drawing for a 
photo-engraving larger than the engraving that is to 
be made from it, a good proportion being to make 
the drawing twice the length the engraving is to be. 
This serves to reduce the magnitude of any rough- 
ness in the lines of the drawing, and, therefore, to 
make the engraving better than the drawing. 

The thickness of the lines in the drawing should be 
made to suit the amount of reduction to be made, be- 
cause the lines are reduced in thickness in the same 
proportion as the engraving is reduced from the 
drawing. Thus the lines on an engraving reduced to 
one-half the dimensions of the drawine" would be 
one-half as thick as the lines on the drawing. 

Drawings for photo-engraving should be made on 
smooth-faced paper; as, for example, on Bristol board; 
and to make the lines clean and clear, the drawing in- 
struments should be in the best of condition, and the 
paper or Bristol board quite dry. The India rubber 
should be used as little as possible on drawings to be 
photo-engraved, because, if used before the lines are 
inked in, it roughens the surface of the paper, and the 
inkine lines will be less smooth and even at their 
edores; and for this reason it is better not to rub out 
any lines until all the lines have been inked in. If used 
to excess after the lines have been inked in it serves 



266 MECHANICAL DRAWING SELF-TAUGHT, 

to reduce the blackness of the Hnes, and may so pale 
them that they will not properly photo-engrave. 

To make a drawing for an engraver in wood it would 
be drawn directly on the face of the box-wood block, 
on which it is to be engraved. The surface of the block 
is first whitened by a white water color, as Chinese 
white. If the drawing that is to be used as a copy is 
on sufficiently thin paper, its outline may be traced 
over by pencil lines, and the copy may then be laid 
face down on the wood block and its edges held to the 
block by wax, the pencilled lines being face to the 
block. The outline may then be again traced over 
with a pencil or pointed instrument, causing the im- 
print of the lead pencil lines to be left on the whitened 
surface of the block. If the copy is on paper too 
thick to be thus employed, a tracing maybe made and 
used as above ; it being borne in mind that the tracing 
must be laid with the pencilled lines on the block, be- 
cause what is the right hand of the drawing on the 
block is the left hand in the print it gives. The 
shading on wood blocks is given by tints of India ink 
aided by pencilled lines, or of course pencilled lines 
only may for less artistic work be used. Another 
method is to photograph the dra\ying direct upon the 
surface of the wood block ; it is unnecessary, however, 
to enter into this part of the subject. 

The third method of producing an engraving from 
a drawing is by means of what is known as the wax 
process. Drawings for this process should be made 
on thin paper, for the following reasons : The process 
consists, briefly stated, in coating a copper plate with 
a layer of wax about V5 inch deep, and in drawing 



EXAMPLES IN LINE-SHADING. 267 

ypon the wax the lines to compose the engraving, 
which lines are produced by means of tools that re- 
move the wax down to the surface of the copper. 

The plate and wax are then placed in a battery and 
a deposit of copper fills in the lines and surface of 
the wax, thus forming the engraving. Now if the 
drawing is made on thin paper, the engraver coats the 
surface of the drawing with a dry red pigment, and 
with a pointed instrument traces over the lines of the 
drawing, which causes them to leave a red imprint on 
the surface of the wax, and after the drawing is re- 
moved the engraver cuts these imprinted lines in the 
wax. If the drawing is on thick paper, this method 
of transferring the drawing to the wax cannot be used, 
and the engraver may take a tracing from the drawing 
and transfer from the tracing to the wax. It is obvi- 
ous, also, that for wax engravings the drawing should 
be made of the same size that the engraving is required 
to be, or otherwise the tracing process described cannot 
be used. 

The wax process is, however, more suitable for en- 
gravings in plain outline only, and is especially excel- 
lent when the parts are small and the lines fall close 
too-ether; or when the letters of reference must of 
necessity be very small. 



CHAPTER XIV. 

EXAMPLES FOR PRACTICE. 

An excellent example in the use of the bow pen is 
a fly-wheel of an engine, such as shown in Figures 
295 and 296. 




Fig. 295. 



Fig. 296. 



It is obvious that all the centres, a, d, c, etc., lay on 

the line of a circle struck from the centre of the 

(268) 



EXAMPLES FOR PRACTICE. 



269 



wheel, and the same remark appHes to the centres d^ e^ 
f, etc. 

At G is shown a cross-section of one arm of the 
wheel taken on the line H H. In drawings of this 
kind it is not necessary to give the cross-section of 
the arm or yoke at more than one place, as one such 
cross-section is sufficient to guide the pattern-maker. 

Fig. 297. 




Fig. 298. 

In those cases in which a line can be drawn through 
a piece of work in such a position that the construc- 
tion of the piece represented in the drawing is alike 
on both sides of the line, the drawing may be made 
l^alf in elevation and half in section, as is shown in 
Figures 297, 298 and 299, which represent a pillow 



2^0 MECHAXICAL DRAWING SELF-TAUGHT. 

block with the half A in side elevation and the lialf B 
in section, so as to show the thickness of the brass. 
All the dimensions could in this example be marked 
upon the side elevation and plan ; hence the end ele- 
vation is superfluous, save as an exercise. 

Figure 300 is a side view and Figure 301 a sec- 
tional side view of a globe valve, such as is used to 
open and close communication in the steam-pipes 
from a boiler or about a building. In this case the 
sectional view. Figure 301, would give both to the pat- 
tern-maker and the machinist all the information they 
would require to make such a valve, since the dimen- 
sions can all be marked thereon. Indeed, this sec- 
tional view is an exact copy of a drawing made by a 
manufacturer of globe valves, and is all that was 
given either to the pattern-maker or the machinist. 

The manufacture of globe valves of ordinary dimen- 
sions has become a special branch of business, and 
such valves can be bought so cheaply that it would 
not pay to make one or two only, even if the castings 
could be got without making a pattern ; hence the 
patterns are made, and the globe valves turned and 
fitted together by men well experienced in their 
manufacture and shape; hence the sectional view 
would give all the information required by them. By 
the addition, however, of the side view, Figure 300, 
and the view of the wheel in Figure 302, the drawings 
are made complete, the dimension figures only requir- 
ing to be marked on, and the kind of metal to be 
specified. The pitches of thread used for globe valves 
are as follows : the pitches for the threads at A and at 
B, Figure 30 1 , are made the same, beincr for valves from i 



EXAMPLES FOR PRACTICE. 



L 



L 



) 



7 




Fig. 300. 



2/2 



MECHANICAL DRAWING SELF-TAUGHT. 




Y\Z. ^oi, 



EXAMPLES FOR PRACTICE. 



•73 



to 2 inch, 14 threads per inch, and for valves from 2^ 
to 3 inch, 1 1 threads per inch* 

The threads at C D are made to conform to 
those on the steam-pipes, the standard pitches being 
as in the following table. It may be remarked, 
however, that the size of a globe valve is taken from 
the diameter of the bore of the pipe it will receive at 
C and D, and that the opening E, wherein the valve 
V seats, should at least equal in diameter the diameter 
of the pipe. 



inch. 



STANDARD PITCHES OF THREAD FOR GLOBE VALVES. 

Diam, of Tube Bore. Outside diam. of Tube. No. of Threads per inch. 

•405 inch. 27 

18 
18 
14 

8 



Ya '■ 


*54 '' 


3/8 " 


•675 - 


^ " 


•84 '' 


% '■ 


1-05 - 


I " 


1-315 " 


1% " 


1-66 •' 


I>^ '■' 


1-9 '* 


2 " 


2-375 " 


2^ " 


2-875 " 


3 " 


3'5 " 


3^ - 


4-0 


4 


4-5 '' 


4^ '' 


5' 


5 '' 


5-563 '' 


6 - 


6625 '^ 


7 '' 


7-625 " 


8 - 


8-625 " 


9 


9-688 '' 


10 '* 


10-75 '' 


II '* 


12 " 


12 " 


13 " 


18 





2^^ MECHAXICAL DRAWING SELF-TALGHT. 

Diam. of Tube Bore. Outside diam. of Tube. No. of Threads per inch. 

13 '' 14 

14 '' 15 '' 8 

15 *^ 16 

16 '' 17 

17 '' 18 
iS '' 19 

The lift of the valve must also be sufficient to leave 
an area of opening at least equal to the bore of the 
pipe, or, what is the same thing, equal to the desig- 
nated size of the globe valve. The amount of lift 
may be determined by the following rule: 

Take the diameter of the bore E, Figure 301, of 
the valve seat and find its circumference and area, and 
divide the latter Into the former, and the quotient is 
the lift for the valve. Example — What Is the lift re- 
quired for a two-inch globe valve? Now the circum- 
ference of 2 Is 6'2832, and the area In a two-Inch 
circle is 3-1416 ; then 6*2832 ^ 3-1416 = -5, and the lift 
for the valve Is -5 or j% Inch, We may prove this as 
follows : 

In Figure 299 it will be seen that the water or 
steam will have with the valve lifted -5 of an Inch, 
an opening to pass through whose depth Is .5 Inch 
and whose circumference (assuming the diameter of 
E to be 2 inches) is 6-2832, as marked, and if we 
multiply these two dimensions together we get the 
area, thus: 6-2832 x '5 = 3'i4i6 = the area of E, 
Figure 301. 

In order to afford a firmer hand grip than Is af- 
forded by the shape of wheel shown In Figure 302, 
the form shown In Figure 303 Is often employed, 



EXAMPLES FOR PRACTICE. 



275 



the one view affording all the information required, 
since upon it all the dimensions can be marked, the 
section of the arm and rim beinof mven. 

Drawings of a Band Sawing Machine are given in 
Figures 304, 305 and 306, which, with the following 
explanation, are taken from " Modern Machine-shop 
Practice." 




Fig. 302. 



"The saw drivinof-wheel D has wrouo^ht-iron arms 
screwed into the wheel hub. The wooden ses^ments 
around the wheel have their grain lengthways, and 
between them are placed pieces of soft wood with 
the grain across the rim. This acts to keep the 



276 



MECHANICAL DRAWING SELF-TAUGHT. 



joints tight, notwithstanding the expansion and con- 
traction of the wood. 

" The upper wheel is adjusted for straining the saw, 
and for leading the saw true, by the following con- 




Fig. 303. 



struction. It is carried in a U-shaped frame F, which 
is pivoted at jk to a slide that is gibbed to the main 
frame, and by operating the screw shown at X the 
frame F is set to the required level. 




— t^^^pcf 



J 



EXAMPLES FOR PRACTICE. 2^^ 

"To regulate the tension of the saw, the hand 
wheel K is operated, which drives the pair of bevel 
gears J and I, the latter of which operates the threaded 
shaft H, whose upper end G connects with the slide 
which carries F. Within G is a spring to act as a 
cushion to the slide, and thus prevent saw breakage 
should a chip pass between the saw and its driving- 
wheel. ^ 

" The saw-guide frame is secured to the main frame 
at m\ m'. Upon the face of ;;^ is a slideway for the 
saw-guide arm n, which may thus be adjusted as 
closely to the upper face of the work as possible. 

"The weight of arm n is counterbalanced by a 
rope passing over the pulley V, and supporting the 
counterbalance weight w. The feed motion is con- 
structed as follows : 

" On the same shaft as the main fast and loose pul- 
leys A B is the feed pulley L, which by belt connec- 
tion drives pulley M, which is on the shaft W, 
upon which is a friction disc N, by means of which 
the rate of feed is regulated. The feed disc N drives 
the wheel O ; the degree of contact between these 
two (N and O) is regulated by means of the weight 
T, on the lever U. 

^ " On the same shaft as the friction wheel O is a 
pinion driving the gear X, which is on the same shaft 
as the pinion Y, which drives the two p;ears Y' 
and Y". 

"Referring now to Figure 304, gear' Y' drives the 
pair of bevel gears Z and Z\ for the feed roll e, and 
the pair of bevel gears shown at Z'\ the feed roll/ 



2-^8 MECHANICAL DRAWING SELF-TAUGHT. 

The gear Y" drives similar gearing for the feed rolls 
d and/', seen in the plan, Figure 306. 

"Referring now to the plan, Figure 306, and the 
front elevation. Figure 304, the feed roll /is carried in 
a frame g, which is fitted on the slide way d, d, and re- 
ceives a screw i, upon which is a hand wheel h; at 
the back of this wheel is the lever/, which is weighted 
as shown, so that the force with which feed roll / 
grips the work is determined by the weighted lever/ 
and may be varied to suit the nature of the work by 
moving the weight along /. 

" The construction of the gear for feed roll / is 
similar, as may be seen in the plan, Figure 306, /' be- 
ing in a slide g', which has a screw i' , and hand wheel 
h\ a weighted lever corresponding to/ acting against 
wheel h' . In proportion as / and / are opened out 
to admit thick stuff or work, the hand wheels h and 
h' respectively are used to screw the screws i and i' 
into their respective slides g and g" , and thus main- 
tain the weighted levers in their requisite horizontal 
positions. The feed rolls e and e' are carried in slides 
c and c' and are adjusted to meet the thickness of the 
work by a hard gearing, which consists of the hand 
wheel a seen in the plan and in the front elevation. 
Figure 305, which drives the pinions b and b\ which 
operate screws for the slides c and c\ the latter being 
a left-hand screw. The front rolls e and e' are, there- 
fore, held in a fixed position, whereas the back ones 
/ and /' may open out under the pressure of the 
weighted levers / and thus accommodate any varia- 
tion in the thickness of the work." 

The rate of work feed is varied to meet the nature 



Ttoner T 




Fig. 3140 



"Work Roller | 



Fig. 306. 



LAN 




I>rivin^ Puileys 

279.) 



EXAMPLES FOR PRACTICE. 279 

of the wood by means of the following construction. 
The friction wheel O and the hand wheel R are con- 
nected by a yoke Q, at the ends of which are the 
joints P, Q, seen in the plan. Hand wheel R is 
threaded to receive the screw S, and it follows that 
by revolving R the friction wheel O may be moved 
towards the centre of the friction disc N, which would 
reduce the velocity with which N would drive O and, 
therefore, reduce the rate of work feed. If the fric- 
tion wheel O be moved from the position it occupies 
in the plan to any point on the other side of the centre 
of the friction disc N, the direction of the work feed 
would obviously be reversed. In making- these draw- 
inors it will be well for the student to draw them at 
least four or five times the size of the en^ravines and 
all three on one sheet of paper. The front elevation, 
Figure 304, should first be drawn, and then the side 
elevation, Figure 305. The centre lines of the shafts 
for the saw driving-wheel D being made to coincide, 
then the heights of all the various pieces or parts 
shown in Figure 304 may be transferred to the draw- 
ing. Figure 305. 

A complete set of workshop drawings for the head- 
stock of a lathe is given in Figures lo-], 307^, 307<3 
and 307^. 

A sectional view of the headstock is shown in Fig- 
ure 307, the back gear being shown detached and 
raised up so as to expose it to view, a plan that is often 
resorted to in order to show as much as possible in 
one drawing. 

Other details of parts of the headstock as they ap- 



28o MECHANICAL DRAWING SELF-TAUGHT. 

pear put together are given in Figure 307a, while in 
307^ and 307^: the various parts are shown separately. 

The signification of the letters on some of these 
drawinors are as follows: 

O. S. D. or O. D. means outside diameter. 

P. D. means pitch diameter. 

P. means pitch. 

T. means teeth. 

Stand, means standard, and when used for bolt 
heads means that they are .to be of standard sizes, 
while as applied to a nut it means that the size and 
the pitch of the thread are both standard. 



gjCHUCKlN 




Fig. 307. '. 



rHE.HEADSTOCJC 
ILL k CO. 



-21 



mmmm 




1 280.) 



}< 4%- _>j K 







d" 








< 2'-^ * 






^_^:V 








/ \ 






t — 




-_'-5«i- 





^ 




Vie'Hole 






-^^ 


-^. 


f' 


1 iJ^i 






1 i^pi 

' ! 1 ' 
III 

L 1 M 






HEAD CAP 



i 




DETAILS 24"cHUCKINq LATHE HEAD STOCK 

A,M..POWELL&CO. 



„ 8«:'. 



Fig. 307-!;. (Page 280.) 



BACK GEAR HANDLk 
C AST IRON - 1 Piece 




bOshings for back gear spindle 

7 Pieces 




FEP.D CON£ 

1 Piece 
5}^- 




Fig. 307^- (Page 280.) 



CHAPTER XV. 
EXAMPLES IN ENGINE WORK. 

In the figures from 308 to 328 inclusive are given 
three examples in engine work, all these drawings 
being from 77^^ American Machinist. Figures 308 to 
314 represent drawings of an automatic high speed 
engine designed and made by Professor John E. and 
William A. Sweet, of Syracuse, New York. Figure 
308 is a side and 309 an end view of the engine. 
Upon a bed-plate is bolted two straight frames, be- 
tw^een which, at their upper ends, the cylinder is se- 
cured by bolts. The guides for the cross-head are 
bolted to the frame, w^hich enables them to be readily 
removed to be replaned when necessary. The hand 
wheel and rod to the right are to operate the stop- 
cock for turnine on and off the steam to the steam- 
chest. 

The objects of the design are as follows : Figure 
310 is a vertical section of the cylinder through the 
valve face, also showing the valve in section, and it 
will be seen that the low^er steam passage enters the 
cylinder its full depth below the inside bottomx, and 
that the whole inside bottom surface of the cylinder 
slopes or inclines tow^ards the entrance of this passage. 
The object of this is to overcome the difficulty expe- 
rienced from the accumulation of water in the cylinder, 

(281) 



282 MECHANICAL DRAWING SELF-TAUGHT. 

which, in the vertical engine, is usually a source of 
considerable annoyance and frequently the cause of 
accident. 

Any water that may be present in the bottom finds 
its way by gravity to the port steam entrance, and is 
forced out by and with the exhaust steam at or before 
the commencement of the return stroke. 

To assist in the escape of water from the top of the 
cylinder, the piston is made quite crowning at that 
end, the effect of which is to collect the water in a 
narrow band, instead of spreading it over a large sur- 
face. This materially assists in its escape, and at the 
same time presents a large surface for the distribution 
of any water that may not find its way out in advance 
of the piston. 

The piston is a single casting unusually long and 
light, and is packed with four spring rings of J inch 
square brass wire. 

The valve is a simple rectangular plate, working 
between the valve face and a cover plate, the cover 
plate being held in its proper position, relative to the 
back of the valve, by steam pressure against its outer 
surface, and by resting against loose distance pieces 
between its inner surface and the valve seat. This 
construction admits of the valve leaving the seat, if 
necessary, to relieve the cylinder from water, as in the 
instance of priming, and also, by the reduction of these 
pieces, admits of ready adjustment to contact, should 
it become necessary. 

The cover plate is provided with recesses on its 
inner surface which exactly correspond with the ports 
in the valve face, and the corresponding ports and re- 



New Automatic High Spe 

ROLLING MILL ENGII 

Cylind«r if x20. 




Fig. 308. fPage 282.) 




S09. (Page 282.) 



m m fTi fT ) i^n 




Fig. 310 — Section of Cylinder and Steam Chest. (Page 283.) 



EXAMPLES IN ENGINE WORK. 



283 




Fig. 311 — Valve Motion. 



284 MECHANICAL DRAWING SELF-TAUGHT. 

cesses are kept in communication with each other by 
means of relief passages in the valve. From this it 
will be seen that the valve is subjected to equal and 
balanced pressure on each of its sides, and hence, is in 
equilibrium. 

The valve is operated through the valve motion, 
shown in Figure 311, the eccentric rod of which hooks 
on a slightly tapered block that turns on the pin of the 
rock arm, like an ordinary journal box. 

The expansion, or cut-off, is automatically regulated 
by the operation of the governor in swinging the 
slotted eccentric in a manner substantially equivalent 
to moving it across the shaft, but is however favorably 
modified by the arrangement of the rock arm, which, 
in combination with the other motions, neutralizes the 
unfavorable operation of the usual shifting eccentric, 
and which, in connection with the large double port 
opening, provides for a good use of steam from o to 
^ stroke. 

The governor shown in Figure 312 is of the disc 
and single ball type, the centrifugal force of the ball 
being counteracted by a powerful spring. Friction is 
reduced to a minimum in the governor connection, by 
introducing steel rollers and hardened steel plates in 
such a manner as to provide rolling instead of sliding 
motion. 

In order that a governor shall correctly perform its 
functions, it is unquestionably necessary that it have 
power largely in excess of the work required of it, and 
also that the friction shall represent a very low per- 
centage of that power. In respect to this, especial 
means have been employed to reduce the friction ; the 



EXAMPLES IN ENGINE WORK. 285 

valve being balanced, requires but little power to move 
it, while the governor ball being made heavy for the 
purpose of counterbalancing the weight of the eccen- 
tric and strap, its centrifugal force when the engine is 



Fig. 312 — Governor. 

at full speed is enormous, the spring to counteract it 
having to sustain from two to three thousana pounds. 
Under these circumstances, as might be expected, the 
regulation is remarkably good. This is a very Impor- 



286 



?.iLCHANICAL DRAWING SELF-TAUGHT. 



tant consideration in an eneine workincr under the 
conditions of a roll-train engine. 

Figure 313 represents a section of the pillow block 
box, crank-pin and wheel, together with the main 
journal. It will be seen that the end of the box next 




Fig. 313 — Section of Pillow Block. 

the crank wheel has a circular groove around its out- 
side, and that a corresponding groove in the crank 
wheel projects over this groove. From this latter 
groove an oil hole of liberal size extends, as shown, to 
the surface of the crank-pin. Any oil placed at the 
upper part of the groove on the box finds its way by 



EXAMPLES IN ENGhWE WORK. 28/ 

gravity into the groove in the crank wheel, and is car- 
ried by centrifugal force to the outside surface of the 
crank-pin ; so that whatever other means of lubrication 
may be employed, this one will always be positive in 
its action. This cut also shows the manner in which 
the box overlaps the main journal and forms the oil 
reservoir. 

Another feature in the construction of this box is 
the means by which it is made to adjust itself in line 
with the shaft. It will be observed that it rests on the 
bottom of the jaws of the frame on two inclined sur- 
faces, which form equal angles with the axis of the 
shaft when in its normal position, and that by 
moving longitudinally in either direction, as may be 
necessary, the box will accommodate itself to a change 
in the alignrnxcnt of the shaft. In order that it may be 
free to move for this purpose it is not fitted with the 
usual fore and aft flanges. By this means any slight 
derangement, as in either the outboard or inboard 
bearinor wearino- down the fastest, is taken care of, the 
movement of the box on the inclined surfaces beino- 
for this purpose equivalent to the operation of a ball 
and socket bearing. 

Figure 314 gives a side and an edge view of the 
connecting rod, the rod being in section in the edge 
view, and the brasses in section lined in both views. 

The cross-head pin, it will be observed, is tapered, 
and is drawn home in the cross-head by a bolt ; the 
sides of the pin are flattened somewhat where the 
journal is, so that the pin may not wear oval, as it is 
apt to do, because of the pull and thrust strain of the 
rod brasses falling mainly upon the top and bottom of 



288 MECHANICAL DRAWING SELF-TAUGHT. 

the journal, where the most wear therefore takes 
place. The brasses at the crossed end are set up by 
a wedge adjustable by means of the screw bolts 
shown. The cross-head wrist pin being removable 
from the cross-head enables the upper end of the rod 
to have a solid end, since it can be passed into place 
in the crossed and the wrist pin inserted through the 
two. The iovv^er ends of the connecting-rod and the 
crank-pin possess a peculiar feature, inasmuch as by 
enlarging the diameter of the crank-pin, the ends of 
the brasses overlap, to a certain extent, the ends of 
the journal, thus holding the oil and affording increased 
lubrication. The segments that partly envelop the 
cross-head pin and crank-pin, and are section lined in 
two directions, producing crossing section lines, cr 
small squares, shaw that the brasses are lined with 
babbitt metal, which is represented by this kind of 
cross-hatching. These drawings are sufficiently open 
and clear to form very good examples to copy and to 
trace on tracing paper. 

Figures 315, 316 and 317 represent, in place upon 
its setting, a 200 horse-power horizontal steam-boiler 
for a stationary engine, and are the design of William 
H. Hoffman. The cross-sectional view of the boiler- 
shell in Figure 316 shows the arrangement of the 
tubes, which, having clear or unobstructed passages 
between the vertical rows of tubes, permits the steam 
to rise freely and assists the circulation of the water. 
The dry pipe (which is also shown in Figure 316) is a 
perforated pipe through which the steam passes to the 
engine cylinder, its object being to carry off the steam 
as dry as possible ; that is to say, without its carrying 




side Sectio 

Fig. 3 ' 



-35- 




^1 -I foot 



ew 

[age 288.) 



EXAMPLES IN ENGINE WORK. 



289 



away with the steam any entrained water that may be 
held in suspension. Figure 315 Is a side elevation 
with the setting shown In section, and Figure 317 is 
an end view of the boiler and setting at the furnace 
end. The boiler is supported on each side by channel 




00000 I ooooo^l 

O-O-O-O-O-4-O-O-O-O-O" 

00000 i 00000 
\ooooo I 00000 

0000 ! 0000 

000 i 000 



Man h~ 





Bole 



BcaleW-lfoot. 
Fig. 316. 

iron columns, these being riveted to the boiler shell 
angle pieces which rest upon the columns. The heat 
and products of combustion pass from the furnace 
along the bottom of the boiler, and at the end pass into 
19 



290 



MECHAXICAL DRAWING SELF-TAUGHT. 



and through the tubes and thence over the top of the 
boiler to the chimney flue. There is shown in the 

-85-' 




.Front Ele oat 1071 
Fig. 317. 

bridge wall an opening, and its service is to admit air 
to die gases after they have passed the bridge wall, and 
thus complete the combustion of such gases as may 



EXAMPLES EV ENGINE WORK. 29 1 

have remained unconsumed in the furnace. The 
cleansing door at one end and that Hned with asbestos 
at the other, are to admit the passage of the tube 
cleaners. The asbestos at the top of the boiler shell 
is to protect it from any undue rise in temperature, 
steam being a poorer conductor of heat than water, 
and it being obvious that if one side of the boiler is 
hotter than the other it expands more from the heat 
and becomes longer, causing the boiler to bend, which 
strains and weakens it. The sides of the setting are 
composed of a double row of brick walls with an air 
space of three inches between them, the object being 
to prevent as far as possible the radiation of heat 
from the walls. The brick-staves are simply stays to 
hold the brick work together and prevent its cracking, 
as it is apt, in the absence of staying, to do. 

Figures from 318 to 330 are working drawings of a 
loo-horse engine, designed also by William H. 
Hoffman. 

Figure 318 represents a plan and a side view of the 
bed-plate with the main bearing and the guide. bars in 
place. The cylinder is bolted at the stuffing box 
end to the bed-plate, and is supported at the outer end 
by an expansion link pivoted to the bed-plate. The 
main bearing is provided with a screw for adjusting 
the height of the bottom piece of the bearing, and 
thus taking up the wear. The guide bars are held to 
the bed in the middle as well as at each end. 

Figures 319 and 320 represent cross sections of the 
bed-plate. 

Figure 321 represents a side elevation of the 
cylinder, and Figure 322 an end view of the same, 



29: 



MECHANICAL DRAWING SEL^-TAUGHT. 



the expansion support being for the purpose of per- 
mitting the cylinder to expand and contract under 




Fig. 320. 

variations of temperature without acting to bend the 
bed-plate, while at the same time the cylinder is sup- 



ii: 



^) 



Bessemer Steel Bars 



s 



_^ u-C 



Fig. 3 



o 



o 



Plan 



% 




)^) 



itiou 

ge 292.) 



i: 




Mtmtlon 

Fig. 31S. (Page 292.) 



^ 




19— Cross Section of Bed Plate near Junction with Cylinder. (Page 291) 



^team Pipe 




Fig. 321 — 100 H. P. Horizontal Steam-Engine — Elev^ 




OF Cylinder— Scale i>^"=i Foot. (Page 292.) 




Fig. 322—100 H. P. Horizontal STEAM-ENHir 

(Pa; 




KD View of Cylinder— Scale i><" = i Foot. 




Fig. 323 — 100 H. P. Engine — Outside Vie 



•Scale 1)^=1 foof 




tvLiNDER AND Steam-Chest. (Page 293.) 



4(»J" 




J&ussw Iron Cover 



.r7 

-51^ 



Fig. 324 — Sectional View of Cylinder and 







1 



fes — Scale i^ Inches =i Foot. (Page 293.) 








Fig. 325— Plan of Cut-off Device. (Page 293.) 




^i^ Centre line of 
^ Main Valve Stem 
3£ovement Sie 



of Cut-off Stems. 




"Fig. 326 — Working Drawing of 100 H. P. Engine — Dij, 




OF Main Valve Motion—Scale f=.i Foot. (Page 293 .} 



; 




Fig- 327 — Working Drawing of 100 H. P. Steam-Engine. 
Wrist Plate. — 3" = i Foot. (See Page 293.) 






fr- 



nn<^'" 



Clig 




Y\<r. 328 — TOO H. P. Horizontal Sti 



--; 


■': \ 


1 i 

Staves 


/ ; ; ; 


;:/ 


\ / 









■-»--=---=-^ 



•iNE — Cross Head. (Page 293.) 




rz 



O 

O 



< 

i 

C/2 



05 
H 

u 

c 
< 



< 



EXAMPLES IN ENGINE WORK. 293 

ported at both ends. The cylinder and cylinder covers 
are jacketted with live steam in the steam-spaces shown. 

A view of the steam-chest side of the cylinder is 
given in Figure 323, and a horizontal cross section 
of the cylinder, the steam-chest and the valves, is 
shown in Figure 324. The main valves are connected 
by a right and left hand screw, to enable their ad- 
justment, as are also the cut-off valves. 

Figures 325 and 326 show the cam wrist plate and 
the cut-off mechanism. The cam wrist plate, which is 
of course vibrated by the eccentric rod, has an inclined 
groove, whose walls are protected from wear by steel 
shoes. In this groove is a steel roller upon a pin at- 
tached to the bell crank operating the main valve stem. 
The operation of the groove is to accelerate the 
motion imparted from the eccentric to the valve at 
one part of the latter's travel, and retard it at another, 
the accelerated portion being during the opening of 
the port for steam admission, and during its closure 
for cutting off, which enables the employment of a 
smaller steam-port than would otherwise be the case. 

The shaft for the cam plate is carried in a bearing 
at one end, and fits in a socket at the other, the socket 
and bearing being upon a base plate that is bolted to 
the bed-plate of the engine; a side view of the con- 
struction being shown in Figure 327. 

Figure 328 represents the cross-head, whose wrist 
pin is let into the cross-head cheeks, so that it may be 
removed to be turned up true. The clip is to prevent 
the piston rod nut from loosening back of itself. 

Figure 329 represents asideview; and Figure 329<2:a 
section through the centre of the eccentric and strap. 



394 



EXAMPLES EV ENGINE WORK, 



The eccentric is let into the strap and is provided with 
an eye to receive a circular nut by means of which 
the length of the eccentric rod may be adjusted, a 
hexagon nut being upon the other or outer end of the 
eye. 

Figure 330 shows the construction of the connect- 
ing rod, the brasses of which are adjustable to take 
up the wear and to maintain them to correct length, 
notwithstanding the wear, by means of a key on each 
side of each pair of brasses, the keys being set up by 
nuts and secured by check nuts. 




"^Kli- 




Fig. 330—100 H. P. Horizontal Steam-Engine— Connecting Rod. (Page 294.) 



I 



INDEX 



Ames' lathe feed motion, drawing a 

part of, 2oS, 
Angle of three lines, one to the other, 
to find, 55, 56. 
of two lines, one to the other, to 
find, 54, 55, 56. 
Angles, acute and obtuse, 57. 
Arc of a circle, an, 50. 
Arcs, construction with four, d'j, 68. 
Arcs for the teeth of wheels, to draw, 

205. 
Arrangement of different views, 94-1 1 1; 
Automatic high speed engine, drawings 

of, 281. 
Axis of a cylinder, 51, 
of an ellipse, 63. 

Ball or sphere, representa:ion of byline- 
shading, 87, 88. 
Band sawing machines, 275. 

w^heels for sawing machines, 275. 
Bed-plate, cross section of, 291. 

plan and side view of, with main 
bearing and guide bars, 291. 
Bell-mouthed body, representation of 

by line-shading, 88, 89. 
Bevelled gear, one-half of, and an edge 
view projected from the same, 
207. 
wheels, 203. 
gears, small, 208. 
wheels, a pair of, in section, 20S. 
Bisected line, 50, 

Black lines of a drawing, how to pro- 
duce, 32. 



Black lines for drawing to be photo - 

engraved, 264 
Blacksmith, drawings for the, 172. 
Blocks, pillow or pillar, 269. 
Boiler, end view of, 289. 

shell, sectional view of, 288. 
Bolt heads and nuts, United States 
standard, 114-118. 
to drav/ a square-headed, 125. 
with a hexagon head, to draw, 

1 1 3-1 14. 
with a square under the head, 

149- 
Bolts and nuts, dimensions of United 
States standard, 117. 
United States standard, forged or 

unfinished, 116. 
nuts and polygons, examples in, 
112-151. 
Bow pen, applying the ink to, 46. 
large, with a removable le^, 22. 
examples in the use of, 268. 
Brass, representation of, by cross-hatch- 
ing, 82. 
Bread for rubbing out, 26. 
Bristol board, use of rubber on, 26. 

Cam, a, and a lever arm in one piece 
on a shaft, a shoe sliding on the 
line, and held against the cam 
face by the rod, to find the po- 
sition of the face of the shoe 
against the cam, 228. 
a full stroke, method of drawing 
or marking out, 237-241. 
(295) 



^g6 



IXDLX. 



Cam, designed to cut off steam at five- 
eighths of the piston stroke, 
244-246 

object of using, instead of eccen- 
tric, 234. 

to draw, 75, 76. 

wrist plate, and cut-off mechanism, 

293- 
Cams, cut-off, employed instead of ec- 
centrics on steamboats, examples 
in drawing, 232. 
finding the essential points of 

drawings of, 241-244. 
necessary imperfections in the op- 
erations of, 247-249. 
part played by the stroke of the 
engine in determining the con- 
formation of, 241. 
three-fourths and seven-eighths, 
246, 247. 
Cap nut, to pencil in a, 145. 
Cast iron, representation of by cross- 
hatching, 82. 
Centre from which an arc of a circle 
has been struck, to find, 52. 
of a circle, 51. 

punch in which the flat sides run 
out upon a circle, the edges form- 
ing curves, 150. 
Chamfer circles of bolt heads, 120-123. 
of Franklin Institute bolt head, 
119. 
Chord of an arc, 50. 
Chuck plate with six slots, to draw, 131. 
Circle, degrees of a, 52-55. 

pencil and circle pen, use of, 43, 44. 

pens, 37, 38. 

that shall pass through any three 

given points, to draw, 51. 
to divide into six divisions, 56, 57. 
Circles, to divide with the triangle, 129, 
for bolt heads, to draw, 128. 
German instrument for drawing, 
44.45- 



Circles, use of the instrument in form- 
ing, 42-45. 
Circumference, 50. 
Collar, a representation of, 96. 
Cone, cylinder intersecting a, 186. 
Connecting rod, 169, 287, 294. 

drawing representing the mo- 
tion which a crank imparts 
to a, 249, 250. 
end, 147. 
Construction of band sawing machines, 

275- 
of band wheels for globe valves, 
274. 
Corner where the round stem meets the 

square under the head, 1 50. 
Coupling rod, working drawings of a, 

169. 
Crank, drawing representing the motion 
which it imparts to a connecting 
rod, 249. 
pin and wheel. 286. 
Cross-hatching or section lining, 77-82. 
made to denote material of which 

the piece is composed, 81, 82. 
may sometimes cause the lines of 
the drawing to appear crooked 
to the eye, 80, 81. 
representation by, of a section of 
a number of pieces one within 
the other, the central bore being 
filled with short plugs, 78, 79. 
representation by, of three pieces 
put together, having slots or key- 
ways through them, 79, So. 
the diagonal lines in, should not 
meet the edges of the piece, 
78. 
Cross-head, 293. 
Cross, use of, to designate a square, 95, 

96. 
Cube, with a hole passing through if, 10 

draw, loi, 102. 
Cupped ring, representation of, 98. 



INDEX. 



297 



Curved outline, representation of, 86, 

87. 
Curve for tooth face, how to find, 198. 

representation of the radius for, 87. 
Curves and Hues, 48-76. 

of gear teeth, names of, 193. 
Curves for moulding cutter, to find the, 
257-263. 

of thread, template for drawing, 
165. 

of wheels, construction, to find, 
204. 

screw threads, drawing, 159. 

templates called, 21. 

use of, in practice, 21. 
Cut-off cams, employed instead of ec- 
centrics on steamboats, examples 
in drawing, 232. 

manner of finding essential points 
of drawings of, 241-244. 

necessary imperfections in the op- 
erations of, 247-249. 

part played by the stroke of the 
engine m determining the con- 
formation of, 241. 

mechanism, 293. 
Cylinder, 291. 

a solid, representation of, 94, 95. 

intersecting a cone, 186. 

of an engine, 293. 
Cylindrical body joining another at a 
right angle, a, 180. 

body whose top face, if viewed 
from one point, would appear as 
a straight line, or if from another 
as a circle, 188. 

piece of wood, which is to be 
squared, and each side of which 
square must be an inch, to find 
the diameter, 136. 

pieces and cubes, representation 
of, 95. 

pieces, representation of, by cross- 
hatching, 77, 78. 



Cylindrical pieces, representation of 
three, one within the other, by 
cross-hatching, 78. 
pieces that join each other, repre- 
sentation of, 86. 
pin line-shaded, representation of, 
86. 

Decagon, a, 63. 
Degrees of a circle, 52-55. 
Diameter of a cylindrical piece of wood, 
which is to be squared, and each 
side of which square must measure 
an inch, to find, 136. 
Diamond, a, 59, 60. 
Different views, arrangement of, 94- 

III. 
Dimension figures in mechanical draw- 
ing, 91. 
Dimensions, marking, 91-93. 
Distances, relative from the eye, repre- 
sentation of, by line-shading, 89. 
Dodecagon, a, 63. 
Dotted lines, use of, 48. 
Double eye, or knuckle-joint, pencil 
lines for, 146. 
or knuckle-joint, with an off-set, 
147. 
Double thread, 156. 
Drawing board, 17, 18. 
fly-wheels, 268. 
size of, 18. 

small, advantage of, to student, 18. 
for engraver on wood, 266. 
gear wheels, 193-222. 
instruments, 22-26. 
parts of, 34. 

selecting and testing, 22. 
paper, 26-29. 
different qualities, kinds and forms, 

26, 27. 
location of, on the drawing boari, 

28, 29. 
the curves for screw threads, 159, 
to scale, making a, 177, 



•298 



INDEX. 



Drawings for engravings, 264-267. 

for engraving, necessity of con- 
forming to tiie particular process 
of, 264. 

for engravings by the wax process, 
267. 

for photo-engraving, for the black- 
smith, 172. 

half in elevation and half in section, 
269. 

Eccentric and strap, 293, 294. 

to find how much motion it will 
give to its rod, 223. 
Edge view of a wheel, to draw, 203. 
Elevation, 94. 

and section, drawings in, 269. 
Ellipse, dimensions of, how taken and 
designated, 63. 
form of a true, 66. 
most correct method of drawing, 

72. 
the, 63-75. 
Elliptical figure, whose proportion of 
width to breadth shall remain 
the same, whatever the length 
of the major axis, 69. 
gearing, examples in drawing, 210- 
213 
Emery paper, use of, on the lining pen, 

37- 
Ennagon, a, 62, 63, 
Engine work, examples of, 281-294. 
working drawings of a 100 horse- 
power, 291. 
Engravings by the wax process, draw- 
ings for, 267. 
Examples for practice, 169-177, 26S- 
280. 
in bolls, nuts and polygons, 112- 

151. 

in drawing elliptical gearing, 210- 

213. 
of engine work, 281-294. 
of work with nine sides, 135. 



Feed motion of a Niles horizontal tool 

work boring mill, 209. 
Five-sided figure, to draw, 132, 133. 
Flanks of teeth to trace hypocycloides, 

for, 200. 
Fly-wheels, drawing, 268. 
Foci of an ellipse, 64. 
Franklin Institute or United States 

Standard for heads of bolts and of 

nuts, basis of, 118. 
Full stroke cam, method of drawing or 

marking out a, 237-241. 

Gear, part of, showing the teeth in, the 
remainder illustrated by circles, 
209. 
teeth, names of the curves and 
lines of, 193. 
. wheels, drawing, 193-222. 
various examples for laying out, 
214-222. 
Gearing, elliptical, examples in drawing, 

210-213. 
General view, 94. 
Geometrical terms, simple explanation 

of, 48. 
Geometry, advantage of, to the draughts- 
man, 48. 
Globe valves, example in, 270. 

sizes of, 273. 
Governor of an engine, 284, 285. 

Hand-wheels for globe valves, 274. 
Hexagonj a, 62, 63. 

head, representation of a piece 

with, 96. 
head, to draw the end view of, 

125, 126, 127. 
headed screw, to draw, 113, 114. 
I radius across corners, 138. 

Hexagonal form, representation of, 98. 
or hexagon heads of bolls, 118, 
119. 
Hole, representation of, by shade or 
shadow line, 8^. 



INDEX. 



299 



Hollows in connection with round 
pieces, representations of, 87-89. 

Hypocycloides for the flanks of teeth, 
to trace, 200. 

India ink, advantages of, in drawing, 30. 
' difference between good and infe- 
rior, 31. 

good, characteristics of, 31. 

Higgins', 30. 

mixing, 25. 

testing, 31, 32. 

the two forms of, 30. 

to be used thick, 32. 

use of, 30. 

use of, on parchment, 32. 
Ink, applying, to the bow pen, 46. 

for drawing, 30-33. 
Instruments, preparation and use of, 

34-47- 
Iron, wrought and cast, representation 
of by cross-hatching, 82. 

Journal, 286. 

Key, a, drawn in perspective, 92, 93. 
drawing of a, 91. 
marking the dimensions of, on a 

drawing, 9*. 
representation of with a shade line, 

84. 
Knuckle-joint, pencil eye for, 146. 
with an off-set, 147. 

Large bow or circle pen, joints of, 23. 

Lathe centre, representation of, 86. 

feed motion, drawing of a part of 
a, 208. 

Lead pencils for drawing, 23. 

Lead, representation of, by cross-hatch- 
ing, 82. 

Left-hand thread, 156. . 

Lever, a, actuating a plunger in a vertical 
line, to find how much a given 
amount of motion of the long arm 
will actuate the plunger, 226. 



Lever and shaft, drawing, 103, 104, 105. 
arm and cam, in one piece on a 
shaft, a shoe sliding on the line, 
and held against the cam face 
by the rod, to find the position 
of the face of the shoe against 
the cam, 228. 
example of the end of a, acting 

directly on a shoe, 225. 
to find how much a given amount 
of motion of a long arm will 
move the short arm of a lever, 
224. 
Levers, two, upon their axles or 
shafts, the arms connected by a link, 
and one arm connected to a rod, 
227. 
Lift of globe valves, 274. 
Light, management of, in mechanical 

drawing, 82, 83. 
Line-shaded engravings, drawing for, 
264. 

shading, 77-90. 

ana drawing for line-shaded 

engravings, 264, 267. 
in perspective drawing of a 
pipe-threading stock and 
die, 85. 
mechanical drawing made to 
look better and show more 
distinctly by, 82. 
simplest form of, 82. 
Lines and curves, 48-76. 

in pencilling, where to begin, 24, 

25- 
Lining pen, 22. 

pen, form of, 34-37. 

pen, use of, with a T square, 45, 

47- 

Link introduced in the place of a roller, 
to find the amount of motion of 
the rod, 226. 
quick return, plotting out the mo- 
tion of a shaper, 250-253. 

Links, pencilling for, 145, 146. 



500 



INDEX. 



Locomotive frame, 174, 
spring, 169. 

Machine screw, to draw, 112, II3. 
iNL.in journal, 286. 
Marking dimensions, 91-93. 
Measuring rules, draughtsman's, 2)?s- 
Mechanical drawings from which en- 
gravings are to be made, 264- 
267. 
motions, plotting, 223-263. 
Motion an eccentric will give to its rod, 
to find, 223. 
a shaper link, quick return, plot- 
ting out, 250-253. 
imparted in a straight line to a 
rod, attached to an eccentric 
strap, to find the amount of, 
229-231. 
which a crank imparts to a con- 
necting rod, 249, 250. 
Motions, plotting mechanical, 223-263. 
Moulding cutter, finding the curves for, 
257-263. 

Niles' horizontal tool work boring mill, 

feed motion of a, 209. 
Nonagon, a, 62. 

Nut, a representation of the shade line 
on, 84. 
cap, to pencil in a, 145. 
to show the thread depth in the 
top or end view of a, 166, 
Nuts and bolts, dimensions of United 

States Standard, 117. 
Nuts and polygons, examples in, 1 1 2- 
151. 

Octagon, a, 62, 63. 
Outline views, 97, 98. 

Taper cutter, the form of the end of, 
25- 

rules or scales, 32. 
Parabola, to draw by lines, 74, 75. 

to draw mechanically, 73, 74. 



Parallel lines, 49, 
Parallelogram, 59, 60. 
Parchment, use of India ink on, 32. 
Pen, German, regulated to draw lines 
of various breadths, 84, 85. 

lining, form of, 34-37. 
Pen point, forming the, 39, 40. 

form of, recently introduced, 39. \ 

points, oilstoning, 36. 

with sapphire points, 85. 
Pens, circle, 37, 38. 

used in drawing, 22. 
Pencil holders for sticks of lead, 24. 

lines in drawing, 23. 

sharpening for fine work, 24. 
Pencilling for a link, having the hubs 
on one side only, 145. 

in a cap nut, 145. 
Penknife and rubber scratching out, 

25- 

Pentagon, a, 62, 63. 

Perimeter, the, 50. 

Periphery, 50. 

Perpendicular line, 49. 

Perspective sketches to denote the 

shape of the piece, 93. 
Photo-engraving, black lines necessary 
in the drawings for, 264. 
drawings for, 264. 
Piece of work should, in mechanical 
drawing, be presented in as few views 
as possible, 94. 
Pillow bloqk, example of, 269. 

box, 286. 
Pin, in a socket, in section, representa- 
tion of, 87, 88. 
Pinion teeth, to draw to the pitch of 

the inner and small end of, 206. 
Pins and discs, discrimination of, in 

mechanical drawing, 96. 
Piston and piston-rod, drawing, 85. 
Pitch circle of the inner and small end 
of, to draw, 206. 
to obtain a division of the lines 
that divide, 167. 



INDEX. 



301 



Pitches of threads for globe valves, 270. 
Plan, 94. 

Plotting mechanical motions, 223-263. 
out the motion of a shaper link 
quick return, 250-253. 
Point, a, 49. 

Points of drawing instruments, 34. 
Polygon of twelve equal sides, to draw, 

129, 130, 
Polygons, bolts and nuts, examples of, 
112-151. 
construction of, 61. 
designation of the angles of, 62, 
names of regular, 62, 63. 
scales giving the lengths of the 
sides of, 135. 
Ports, drawing, 85. 
Preparation and use of the instruments 

34-47- 
Produce line, 50. 

Projecting one view from another, 106. 
Projections, 178-192. 
Protractors, 53. 
Pulleys, regulating tension of, for 

sawing machines, 277. 

Quadrangle, quadrilateral or tetragon, 

59. 

Quadrant of a circle, 50. 

Quick return motion, Whitworth, plot- 
ting out, 253-256. 

Radius across corners of a hexagon, 

138. 
Reducing scales, 175. 
Rectangle, a, 59, 60. 
Rectangular piece, a, to draw in two 
views, 98, 99. 
requires two or three views, 96 97. 
Right line, a, 49. 

representation of, 96. 
Red ink, marking dimensions of me- 
chanical drawings in, 91. 
Rhomboid, a, 60. 
Rhomb, rhombus or diamond, 54, 60, 



Ring with a hexagon cross section, 98. 
Rivet, side and end views of, 49. 
Roller, example of a short arm having 

a, acting upon a larger roller, 225. 
Rod, attached to an eccentric strap, to 
find the amount of motion im- 
parted in a straight line to a, 
229-231. 
end with a round stem, 148. 
Round stem, a representation of, 96. 

top and bottom thread, 156. 
Rubber, 25. 

form of, 26. 
proper uses of, 25. 
sponge, 26. 
the use of, 25. 

to be used on Bristol board, 26. 
velvet, 26. 
Rule, steel, 32. 

Sawing machine, example of, 275. 
Sapphire points, pen with, 85. 
Scale for diameter of a regular polygon, 
140. 

of tooth proportions, 195. 

triangular, 33. 
Scales, for measurement and drawing, 
32. 

reducing, 175. 
Scratching out, 25. 
Screw machine, to draw, 112, 113. 

thread. United States standard, to 
draw, 159, 160. 

threads and spirals, 152-168. 

threads, drawing the curves for, 

159- 
threads for small bolts, with the 
angles of the threads drawn in, 

152-155- 
threads of a large diameter, 156. 
Section lining or cross-hatching, 77-82. 

and elevation, drawings in, 269. 
Sectional view of a section of a wheel, 
for showing dimensions through arms 
and hub, 202. 



302 

Sector of a circle, 51. 
Segment of a circle, 50. 
Semicircle, 51. 

Shade curve, representation of, 87. 
line produced for circles, 84. 
line, produced in straight lines, 84. 
or shadow line, 82. 
Shading by means of lines to distinguish 
round from flat surfaces, and 
denote relative distances of sur- 
faces, 85. 
Shapes of wheels for globe valves, 274. 
Shadow line, £2. 

lines and line shading, 77-90. 
Shaft for cam plate, 293, 
Shaper link, quick return, plotting out 

the motion of a, 250-253. 
Shoe against a cam, to find the position 

of the face of, 228. 
Side elevation, drawing a, 106. 



INDEX. 



Steam chest and valves, 293. 

chest side, and horizontal cross 
section of cylinder, 293. 
Steel, representation of by cross-hatch- 
ing, 82. 
square, improved, with pivoted 
blade, 19. 
Steps, to draw a piece containing, 99- 

lOI. 

Straight line in geometry termed a 
right line, 49. 
or lining pen, use of with a T 
square, 45» 47- 
Stud, to draw a, 142. 
Stuffing-box and gland, 169. 
Surface of the paper, condensing after 
rubbing out, 25. 

Tacks for drawing paper, 27, 28. 
Tangent, 51. 



Sides or flats of work, to find the lengths ' Taper 



m 



of, 135, 136. 
Sizes of globe valves, 273, 274. 
Slots not radiating from a centre, to 
draw, 131, 132. 
radiating from a centre, 131. 
Spiral spring, to draw, 166. 

wound round a cylinder, whose 
end is cut off at an angle, 178. 
Spirals and screw threads, 152-168, 
Sponge, rubber, 26, 
Spring bow pencil, for circles, 22.| 
pen, for circles, 22, 23. 
spiral, to draw, 166. 
Spur wheel teeth, how to draw, 194. 
Square, a, 59, 60. 

body, which measures one inch on 
each side, to find what it meas- 
ures across the corners, 136. 
part, a representation of, 96, 
parts, use of a cross to designate, 

95, 96. 
thread, to draw a, 162-164. 
Steam boiler, horizontal, for stationary 
engine, 2S8. 



or conical hole, to denote 
drawing, 102. 
sides in a drawing, 102, 103, 
Tees, 180. 

Teeth of wheels, rules for drawing 
203. 
pinion, to draw the pitch of 
the inner and small end of 
206. « 

spur wheel, how to draw, 194. 
to trace hypocycloides for 
flanks of, 200. 
Template for drawing the curves 

thread, 165. 
Templates called curves, 21. 
T square, 18, 19. 
T square, different kinds of, 19. 
Tetragon, a, 59, 62, 63. 
Thread, a double, 156. 

a round top and bottom, 156. 
depth in the top or end view of a 

nut, to show, 166. 
left hand, 156. 
square, to draw a, 1 62-164. 
Whitworth, 156. 



the 



of 



INDEX. 



303 



Threads of a large diameter, 156. 
Thumb tacks for drawing paper, 27. 
Tooth face, how to find the curve for, 
198. 

proportions, Willis' scale of, 195. 
Tracing cloth, 29. 

paper, 29. 
Trammel, use of, in drawing an ellipse, 

72. 
Trapezium, 60. 
Trapezoid, a, 60. 
Triangle, equilateral, 58, 59. 

isosceles, 58, 59. 

obtuse, 58. 

right angle, 58. 

scalene, 59. 

use of in dividing circles, 129. 

use of in drawing polygons, 129, 
130. 

use of to draw slots radiating from 
a centre, 131. 
Triangles, 19-21, 58-60. 

requirements in use of, 20, 21. 

to draw, 133. 

using with the square, 20. 
Triangular scale, '^,'^. 
Trigon, a, 62, 63. 

True ellipse, a near approach to the 
form of, 69-72. 

United States standard bolts and nuts, 
114-118. 
standard thread, to draw, 159, 160. 

Valve of an engine, 282-284. 
Valves, 293. 



Valves, globe, 270, 
Vertex, the, 59. 

Views, different arrangement of, 94-i 1 1. 
of a piece of work, designations 



of. 



104. 



of a piece, two systems of placing, 
106-111. 

Washer, a, representation of the shadow 

side of, 83. 
Wax process, drawings for engravings 
by, 267. 
engraving from a print from a 
wood engraving, 267. 
Wedge-shaped piece, representation of 

a, 07. 
Wheel, edge view of a, to draw, 203. 
sectional view of a section of a, 
202. 
Wheels, construction, to find the curves 
of, 204. 
to draw the arcs for the teeth of, 
205. 
Whitworth thread, 156. 

quick return motion, plotting out, 
253-256. 
Willis' scale of tooth proportions^ 195. 

application of, 197. 
Wood engraving, drav/ing for, 264. 
representation of by cross-hatching, 

82. 
representation of, regular and ir- 
regular shade lines in, 90, 
Wrought iron, representation of by 
cross-hatching, 82. 



OF 

^miM and Scientific M\^ 

PUBLISHED BY 

Henry Carey Baird & Co, 

INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS, 

810 Walnut Street, Philadelphia. 



fl^ Any of the Books comprised in this Catalogne will be sent by mail, free of 
postage, to any address in the world, at the publication prices, 

«2r- A Descriptive Catalogue, 84 pages, 8vo., will be sent free and free of postage,- 
to any one in any part of the world, who will furnish his address. 

*^- Where not otherwise stated, all of the Books in this Catalogue are bound 
in muslin. 



AMATEUR MECHANICS' WORKSHOP: 

A treatise containing plain and concise directions for the manipula- 
tion of Wood and Metals, including Casting, Forging, Brazing, 
Soldering and Carpentry. By the author of the " Lathe and Its 
Uses." Seventh edition. Illustrated. 8vo. ... $3.00 

ANDRES.— A Practical Treatise on the Fabrication of Volatile 
and Fat Varnishes, Lacquers, Siccatives and Sealing 
\yaxes. 
From the German of Erwin Andres, Manufacturer of Varnishes 
and Lacquers. With additions on the Manufacture and Application 
of Varnishes, Stains for Wood, Horn, Ivory, Bone and Leather. 
From the German of Dr. Emil Wimckler and Louis E. Andes. 
The whole translated and edited by William T. Brannt. With 1 1 
illustrations. l2mo. $3- 50 

ARLOT.— A Complete Guide for Coach Painters : 

Translated from the French of M. Arlot, Coach Painter; for 
eleven years Foreman of Painting to M. Eherler, Coach Maker, 
Paris. By A. A. Fesquet, Chemist and Engineer. To which is 
added an Appendix, containing Information respecting the Materials 
and the Practice of Coach and Car Painting and Varnishing in the 
United States and Great Britain. i2mo. . . . j?i.25 

CO 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



ARMENGAUD, AMOROUX, AND JOHNSON.— The Practi 
cal Draughtsman's Book of Industrial Design, and Ma- 
chinist's and Engineer's Drawing Companion : 

Forming a Complete Course of Mechanical Engineering and Archi- 
tectural Drawing. From the French of M. Armengaud the elder, 
Prof, of Design in the Conservatoire of Arts and Industry, Paris, and 
MM. Armengaud the younger, and Amoroux, Civil Engineers. Re- 
written and arranged wdth additional matter and plates, selections from 
and examples of the most useful and generally employed mechanism 
of the day. By William Johnson, Assoc. Inst. C. E. Illustrated 
by fifty folio steel plates, and fifty wood-cuts. A new edition, 4to., 
half morocco ......... $10.00 

ARMSTRONG.— The Construction and Management of Steam 
Boilers : 
By R. Armstrong, C. E. With an Appendix by Robert Mallet, 
C. E., F. R. S. Seventh Edition. Illustrated, i vol. i2nto. 75 

ARROWSMITH.— Paper-Hanger's Companion : 

A Treatise in which the Practical Operations of the Trade are 
Systematically laid down : with Copious Directions Preparator)' to 
Papering ; Preventives against the Effect of Damp on Walls ; the 
various Cements and Pastes Adapted to the Several Purposes of 
the Trade ; Observations and Directions for the Panelling and 
Ornamenting of Rooms, etc. By James Arrowsmith. i2mo., 
cloth $1.25 

ASHTON. — The Theory and Practice of the Art of Designing 
Fancy Cotton and Woollen Cloths from Sample : 

Giving full instructions for reducing drafts, as well as the methods of 
spooling and making out harness for cross drafts and finding any re- 
quired reed; with calculations and tables of yarn. By Frederic T. 
Ashton, Designer, West Pittsfield, Mass. With fifty-two illustrations. 
One vol. folio $!0.oo 

AUERBACH— CROOKES.— Anthracen : 

Its Constitution, Properties, Manufacture and Derivatives, including 
Aitificial Alizarin, Anthrapurpurin, etc.,, with their applications in 
Dyeing and Printing. By G. Auerrach. Translated and edited 
fiom the revised manuscript of the Author, by Wm. Crookes, F. R. 
S., Vice-President of the Chemical vSociety. 8vo. . . $5.00 

BAIRD.— Miscellaneous Papers on Economic Questions. 
By Henry Carey Baird. {In prepaiation.) 

BAIRD.— The American Cotton Spinner, and Manager's ar-,d 
Carder's Guide: 
A Practical Treatise on Cotton Spinning ; giving the Dimensions and 
Speed of Machinery, Draught and Twist Calculations, etc. ; with 
notices of recent Improvements: together with Rules and Examples 
lor making changes in the sizes and numbers of Roving and Yarn. 
Compiled from the papers of the late Robert H. Bairu. i2nio. 

31 50 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



BAIRD. — Standard Wages Computing Tables : 

An Improvement in all former Methods of Computation, so arranged 
that wages for days, hours, or fractions of hours, at a specified rate 
per day or hour, may be ascertained at a glance. By T. Spangler 
Baird. Oblong folio . . . . . . . $500 

BAKER. — Long-Span Railway Bridges : 

Comprising Investigations of the Comparative Theoretical and 
Practical Advantages of the various Adopted or Proposed Type 
Systems of Construction; with numerous Formulae and Tables. By 
B. Baker. i2mo. ^1.50 

BAKER.— The Mathematical Theory of the Steam-Engine : 
With Rules at length, and Examples worked out for the use of 
Practical Men. By T. Baker, C. E., with numerous Diagrams. 
Sixth Edition, Revised by Prof. J. R. YoUNG. i2mo. . 75 

BARLOW. — The History and Principles of Weaving, by 
Hand and by Power : 
Reprinted, with Considerable Additions, from " Engineering," with 
a chapter on Lace-making Machinery, reprinted from the Journal of 
the " Society of Arts." By Alfred Barlow. With several hundred 
illustrations. 8vo., 443 pages ^10.00 

BARR. — A Practical Treatise on the Combustion of Coal: 
Including descriptions of various mechanical devices for the Eco- 
nomic Generation of Heat by the Combustion of Fuel, whether solid, 
liquid or gaseous. 8vo . $2.50 

BARR. — A Practical Treatise on High Pressure Steam Boilers : 
Including Results of Recent Experimental Tests of Boiler Materials, 
together with a Description of Approved Safety Apparatus, Steam 
Pumps, Injectors and Economizers in actual use. By Wm. M. Barr. 
204 Illustrations. 8vo. ....... $3-00 

BAUERMAN.— A Treatise on the Metallurgy of Iron : 

Containing Outlines of the History of Iron Manufacture, Methods of 
Assay, and Analysis of Iron Ores, Processes of Manufactux-e of Iron 
and Steel, etc., etc. By H. Bauerman, F. G. S., Associate of the 
Royal School of Mines. Fifth Edition, Revised and Enlarged. 
Illustrated with numerous Wood Engravings from Drawings by J. B, 
Jordan. i2mo ^2.oc 

BAYLES.— House Drainage and Water Service : 

In Cities, Villages and Rural Neighborhoods. With Incidental Con. 
sideration of Certain Causes Affecting the Healthfulness of Dwell- 
ings. By James C. Bayles, Editor of " The Iron Age " and " The 
Metal Worker." With numerous illustrations. Svo. cloth, $3. 00 

BEANS. — A Treatise on Railway Curves and Location of 
Railroads : 
By E. W. Beans, C. E. Illustrated. i2mo. Tucks . $1.50 

BECKETT. — A Rudimentary Treatise on Clocks, and Watches 

and Bells : 

By Sir Edmund Beckett, Bart., LL. D., Q. C. F. R. A. S. With 

numerous illustrations. Seventh Edition, Revised and Enlarged. 

l2mo $2.2$ 



HENRY CAREY BAIRD & CO.'S CATALOGUE, 



BELL. — Carpentry Made Easy: 

Or, The Science and Art of Framing on a New and Improved 
System- With Specific Instructions for Building Balloon Frames, Barn 
Frames, Mill Frames, Warehouses, Church Spires, etc. Comprising 
also a System of Bridge Building, with Bills, Estimates of Cost, and 
valuable* Tables, Illustrated by forty-four plates, comprising /learly 
200 figures. By William E. Bell, Architect and Practical Builder. 
8vo. ^5.00 

BEMROSE. — Fret-Cutting and Perforated Carving : 

With fifty-three practical illustrations. By W. Bemrose, Jr. I vol- 
quarto $3-00 

BEMROSE.— Manual of Buhl-work and Marquetry: 

With Practical Instructions for Learners, and ninety colored designs. 
By W. Bemrose, Jr. i vol. quarto .... $3.00 

BEMROSE.— Manual of Wood Carving: 

With Practical Illustrations for Learners of the Art, and Original and 
Selected Designs. By William Bemrose, Jr. With an Intro- 
duction by Llewellyn Jewitt, F. S. A., etc. With 128 illustra- 
tions, 4to. $3-oo 

BILLINGS.— Tobacco : 

Its History, Variety, Culture, Manufacture, Commerce, and Various 
Modes of Use. By E. R. Billings. Illustrated by nearly 200 
engravings. 8vo $3.00 

BIRD. — The American Practical Dyers* Companion: 

Comprising a Description of the Principal Dye-Stuffs and Chemicals 
used in Dyeing, their Natures and Uses ; Mordants, and How Made ; 
with the best American, English, French and German processes for 
Bleaching and Dyeing Silk, Wool, Cotton, Linen, Flannel, Felt, 
Dress Goods, Mixed and Hosiery Yarns, Feathers, Grass, Felt, Fur, 
Wool, and Straw Hats, Jute Yarn, Vegetable Ivory, Mats, Skins, 
Furs, Leather, etc., etc. By Wood, Aniline, and other Processes, 
together with Remarks on Finishing Agents, and Instructions in the 
Finishing of Fabrics, Substitutes for Indigo, Water-Proofing of 
Materials, Tests and Purification of Water, Manufacture of Aniline 
and other New Dye Wares, Harmonizing Colors, etc., etc. ; embrac- 
ing in all over 800 Receipts for Colors and Shades, accompanied by 
170 Dyed Samples of Ra7u Materials and Fabrics. By F. J. BiRD, 
Practical Dyer, Author of " The Dyers' Hand-Book." 8vo. ^lO-OO 

BLINN. — A Practical Workshop Companion for Tin, Sheet- 
Iron, and Copper-plate Workers : 
Containing Rules for describing various kinds of Patterns used by 
Tin, Sheet-Iron and Copper-plate Workers; Practical Geometry; 
Mensuration of Surfaces and Solids ; Tables of the Weights of 
Metals, Lead-pipe, etc. ; Tables of Areas and Circumferences 
of Circles; Japan, Varnishes, Lackers, Cements, Compositions, etc., 
etc. By Leroy J. Blinn, Master Mechanic. With over One 
Hundred Illustrations, '-^mo. $2.50 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



BOOTH. — Marble Worker's Manual: 

Containing Practical Information respecting Marbles in general, their 
Cutting, Working and Polishing ; Veneering of Marble ; Mosaics ; 
Composition and Use of Artificial Marble, Stuccos, Cements, Receipts, 
Secrets, etc., etc. Translated from the French by M. L. Booth. 
With an Appendix concerning American Marbles. i2mo., cloth $1.50 
BOOTH and MORFIT.— The Encyclopaedia of Chemistry, 
Practical and Theoretical : 
Embracing its application to the Arts, Metallurgy, Mineralogy, 
Geology, Medicine and Pharmacy. By James C. Booth, Meher 
and Refiner in the United States Mint, Professor of Applied Chem- 
istry in the Franklin Institute, etc., assisted by Campbell Morfit, 
author of " Chemical Manipulations," etc. Seventh Edition. Com- 
plete in one volume, royal 8vo., 978 pages, with numerous wood-cuts 
and other illustrations .... . . . ^^5.00 

BRAMWELL.— The Wool Carder's Vade-Mecum: 

A Complete Manual of the Art of Carding "i'extde Fabrics. By W. 
C. Bramwell. Third Edition, revised and enlarged. Illustrated. 

Pp. 400. l2mo. $2.50 

BRAN NT.— A Practical Treatise on Animal and Vegetable 

Fats and Oils : 
Comprising both Fixed and Volatile Oils, their Physical and Chemi- 
cal Properties and Uses, the Manner of Extracting and Refining 
them, and Practical Rules for Testing them; as well as the Manu- 
facture of Artificial Butter, Lubricants, including Mineral Lubricating 
Oils, etc., and on Ozokerite. Edited chiefly from the German of 
Drs. Karl Schaedler, G. W. Askinson, and Richard Brunner, 
with Additions and Lists of American Patents relating to the Extrac- 
tion, Rendering, Refining, Decomposing, and Bleaching of Fats and 
Oils. By William T. Brannt. Illustrated by 244 engravings. 

739 pages. Svo ^7.50 

BRANNT.— A Practical Treatise on the Manufacture of Soap 

and Candles : 
Based upon the most Recent Experiences in the Practice and Science ; 
comprising the Chemistry, Raw Matei'ials, Machinc'-v. and Utensils 
and Various Processes of Manufacture, including a great variety of 
formulas. Edited chiefly from the German of Dr. C. Deite, A. 
Engelhardt, Dr. C. Schaedler and others ; with additions and lists 
of American Patents relating to these subjects. By Wm. T. Brannt. 
Illustrated by 163 engravings. 677 pages. Svo. . . $7.50 

BRANNT.— A Practical Treatise on the Raw Materials and the 
Distillation and Rectification of Alcohol, and the Prepara- 
tion of Alcoholic Liquors, Liqueurs, Cordials, Bitters, etc. : 

Edited chiefly from the German of Dr. K. Stammer, I )r. F. Eisner, 
and E. Schubert. By Wm. T. Brannt. Illustrated by thirty-one 
engravings. l2mo. . . » . ... $2.50 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



BRANNT— WAHL.— The Techno- Chemical Receipt Book: 

Containing several thousand Receipts covering the latest, most Im 
portant, and most useful discoveries in Chemical Technology, and 
their Practical Application in the Arts and the Industries. Edited 
chiefly from the German of Drs. Winckler, Eisner, Keintze, Mier- 
zinski, Jacobsen, Koller, and Heinzerling, with additions by Wm. T. 
Brannt and Wm. H. Wahl, Ph. D. Illustrated by 78 engraving,, 
l2mo. 495 page- ... . .^2 03 

BROWN. — Five Hundred and Seven Mechanical Movements. 
Embracing all those which are most imp>ortant in Dynamics, Hy- 
draulics, Hydrostatics, Pneumatics, Steam-Engines, Mill and othei 
Gearing, Presses, Horology and Miscellaneous Machinery; and in- 
cluding many movements never before published, and several of 
which have only recently come into use. By Henry T. Brown. 
i2mo $1.00 

BUCKMASTER.— The Elements of Mechanical Physics : 
By J. C. BuCKMASTER. Illustrated with numerous engravings. 
i2mo ^1.50 

BULLOCK.— The American Cottage Builder : 

A Series of Designs, Plans and Specifications, from $200 to $20,000, 
for Homes for the People ; together with Warming, Ventilation, 
Drainage, Painting and Landscape Gardening. By JOHN BuLLOCK, 
Architect and Editor of "The Rudiments of Architecture and 
Building," etc., etc. Illustrated by 75 engravings. 8vo. S3.50 

BULLOCK. — The Rudiments of Architecture and Building: 
For the use of Architects, Builders, Draughtsmen, Machinists, En- 
gineers and Mechanics. Edited by John Bullock, author of " The 
American Cottage Builder." Illustrated by 250 Engravings. 8vo. $3.30 

BURGH.— Practical Rules for the Proportions of Modem 
Engines and Boilers for Land and Marine Purposes. 
Bv N. P. Burgh, Engineer. i2mo. .... J^i-SC 

BYLES.— Sophisms of Free Trade and Popular Political 

Economy Examined. 

By a Barrister (Sir John Barnard Byles, Judge of Common 

Pleas). from the Ninth English Edition, as published by the 

Manchester Reciprocity Association. i2mo, . . . $1.25 

BOWMAN.— The Structure of the Wool Fibre in its Relation 
to the Use of W^ool for Technical Purposes : 
Being the substance, with additions, of Five Lectures, delivered at 
the request of the Council, to the members of the Bradford Technical 
College, and the Society of Dyers and Coloiists. By F. H. Bow- 
man, D. Sc, F. R. S. E., F, L. S. Illustrated by 32 engravings, 
"^vo. $6.50 

BYRNE. — Hand-Book for the Artisan, Mechanic, and Engi- 
neer: 
Comprising the Grinding and Sharpening of Cutting Tools, Abrasive 
Processes, Lapidary Work, Gem and Glass Engraving, Varnishing 
and Lackering, Apparatus, Materials and Processes for Grinding and 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



Polishing, etc. By Oliver Byrne. Illustrated by 185 wood en- 
gravings. 8vo, $5.00 

BYRNE.— Pocket-Book for Railroad and Civil Engineers : 

Containing New, Exact and Concise Methods for Laying out Railroad 
Curves, Switches, Frog Angles and Crossings ; the Staking out of 
work; Levelling; the Calculation of Cuttings; Embankments; Earth- 
work, etc. By Oliver Byrne. iSmo., full bound, pocket-book 
form ^1-75 

^YRNE.— The Practical Metal- Worker's Assistant : 

Comprising Metallurgic Chemistry ; the Arts of Working all Metals 
and Alloys ; Forging of Iron and Steel ; Hardening and Tempermg ; 
Melting and Mixing; Casting and Founding ; Works in Sheet Metal; 
the Processes Dependent on the Ductility of the Metals; Soldering; 
and the most Improved Processes and Tools employed by Metal- 
workers. With the Application of the Art of Electro-Metallurgy to 
Manufacturing Processes ; collected from Original Sources, and from 
the works of Holtzapfifel, Bergeron, Leupold, Plumier, Napier, 
Scoffern, Clay, Fairbairn and others. By Oliver Byrne. A new, 
revised and improved edition, to which is added an Appendix, con- 
taining The Manufacture of Russian Sheet-Iron. By John Percy, 
M. D., F. R. S. The Manufacture of Malleable Iron Castings, and 
Improvements in Bessemer Steel. By A. A. Fesquet, Chemist and 
Engineer, With over Six Hundred Engravings, Illustrating every 
Branch of the Subject. 8vo ^7.00 

BYRNE.— The Practical Model Calculator: 

For the Engineer, Mechanic, Manufacturer of Engine Work, Navai 
Architect, Miner and Millwright. By Oliver Byrne. 8vo., nearly 
«oo pages ......... $4.56 

CABINET MAKER'S ALBUM OF FURNITURE: 

Comprising a Collection of Designs for various Styles of Furniture. 
Illustrated by Forty-eight Large and Beautifully Engraved Plates. 
Oblong, 8vo J^S-SO 

CALLINGHAM.— Sign Writing and Glass Embossing: 

A Complete Practical Illustrated Manual of the Art. By James 
Calltngham. i2mo $1.50 

CAMPIN. — A Practical Treatise on Mechanical Engineering: 
Comprising Metallurgy, Moulding, Casting, Forging, Tools, Work, 
shop Machinery, Mechanical Manipulation, Manufacture of Steam- 
Engines, etc. With an Appendix on the Analysis of Iron and Iron 
Ores. By Francis Campin, C. E. To which are added, Observations 
on the Construction of Steam Boilers, and Remarks upon Furnaces 
used for Smoke Prevention; with a Chapter on Explosions. By R. 
Armstrong, C. E., and John Bourne. Rules for Calculating the 
Change Wheels for Screws on a Turning Lathe, and fur a Wheel- 
cutting Machine. By J. La Nicca, Management of Steel, Includ- 
ing Forging, Hardening, Tempering, Annealing, Shrinking and 
Expansion; and the Case-hardening of Iron. By G. Ede, 8vi-. 
lilustrated with twenty-nine plates and 100 wood engravings i^S.cxj 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



CAREY.— A Memoir of Henry C. Carey. 

By Dr. Wm. Elder. With a portrait. 8vo., cloth . . 75 

CAREY.— The Works of Henry C. Carey : 

Harmony of Interests : Agricultural, Manufacturing and Commer- 
cial. 8vo. . . ^1.50 

Manual of Social Science. Condensed from Carey's " Principles 
of Social Science." By Kate McKean. i vol. i2mo. . $2.25 
Miscellaneous Works. With a Portrait. 2 vols. 8vo. ;J6.oo 

Past, Present and Future. 8vo $2.50 

Principles of Social Science. 3 volumes, 8vo. . . $10,00 
The Slave-Trade, Domestic and Foreign; Why it Exists, and 
How it may be Extinguished (1853). 8vo. . . . $2.00 

The Unity of Law : As Exhibited in the Relations of Physical, 
Social, Mental and Moral Science (1872). 8vo. . . $3-S^ 

CLARK. — Tramways, their Construction and Working : 

Embracing a Comprehensive History of the System. With an ex' 
haustive analysis of the various modes of traction, including horse- 
power, steam, heated water and compressed air; a description of the 
varieties of Rolling stock, and ample details of cost and working ex- 
penses. By D. Kinnear Clark. Illustrated by over 200 wood 
engravings, and thirteen folding plates. 2 vols. 8vo. . $12.50 

COLBURN.— The Locomotive Engine : 

Including a Description of its Structure, Rules for Estimating its 
Capabilities, and Practical Observations on its Construction and Man- 
agement. By Zerah Colburn. Illustrated. i2mo. . ^I.oo 

COLLENS.— The Eden of Labor; or, the Christian Utopia. 
By T. Wharton Collens, author of " Humanics," "The History 
of Charity," etc. i2mo. Paper cover, $1.00; Cloth . iSl.25 

COOLEY.— A Complete Practical Treatise on Perfumery : 
Being a Hand-book of Perfumes, Cosmetics and other Toilet Articles. 
With a Comprehensive Collection of Formulae. By Arnold J. 
CooLEY. i2mo ,$1.50 

COOPER.— A Treatise on the use of Belting for the Trans- 
mission of Power. 
With numerous illustrations of approved and actual methods of ar- 
ranging Main Driving and Quarter Twist Belts, and of Belt Fasten.- 
ings. Examples and Rules in great number for exhibiting and cal- 
culating the size and driving power of Belts. Plain, Particular and 
Practical Directions for the Treatment, Care and Management of 
Belts. Descriptions of many varieties of Beltings, together with 
chapters on the Transmission of Power by Ropes; by Iron and 
Wood Frictional Gearing; on the Strength of Belting Leather; and 
on the Experimental Investigations of Morin, Briggs, and others. Ey 
John H. Cooper, M. E. 8vo 33-50 

CRAIK.— The Practical American Millwright and Miller. 

By David Craik, Millwright. Illustrated by numerous wood en- 
gravings and two folding plates. 8vo i^S-OO 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



CREW.— A Practical Treatise on Petroleum : 

Comprising its Origin, Geology, Geographical Distribution, Histo?y, 
Chemistry, Mining, Technology, Uses and Transportation. Together 
with a Description of Gas Wells, the Application of Gas as Fuel, etc. 
By Benjamin J. Crew. With an Appendix on the Product and 
Exhaustion of the Oil Regions, and the Geology of Natural Gas in 
Pennsylvania and New York. By Charles A. Ashburner, jM. S 
Geologist in Charge Pennsylvania Survey, Philadelphia. Illustrated 
by 70 engravings. 8vo. 508 pages .... $5.00 

CROOKES.— Select Methods in Chemical Analysis (Chiefly 
Inorganic) : 
By William Crookes, F. R. S., V. P. C. S. 2d edition, re-writtm 
and greatly enlarged. Illustrated by 37 wood-cuts. 725 pp. 8vo. 38.00 

CRISTIANI. — A Technical Treatise on Soap and Candles : 
With a Glance at the Industry of Fats and Oils. By R. S. Cris 
TIAN I, Chemist. Author of " Perfumery and Kindred Arts." Illus- 
trated by 176 engravings. 58 1 pages, 8vo. . . . $7.50 

CRISTIANI.— Perfumery and Kindred Arts: 
A Comprehensive Treatise on Perfumery, containing a History of 
Perfumes from the remotest ages to the present time. A complete 
detailed description of the various Materials and Apparatus used in 
the Perfumer's Art, with thorough Practical Instruction and careful 
Formulae, and advice for the fabrication of all known preparations of 
the day, including Essences, Tinctures, Extracts, Spirits, Waters, 
Vinegars, Pomades, Powders, Paints, Oils, Emulsions, Cosmetics, 
Infusions, Pastilles, Tooth Powders and Washes, Cachous, Hair Dyes, 
Sachets, Essential Oils, Flavoring Extracts, etc. ; and full details for 
making and manipulating Fancy Toilet Soaps, Shaving Creams, etc., 
by new and improved methods. With an Appendix giving hints and 
advice for making and fermenting Domestic Wines, Cordials, Liquors, 
Candies, Jellies, Syrups, Colors, etc., and for Perfuming and Flavor- 
ing Segars, Snuff and Tobacco, and Miscellaneous Receipts for 
various useful Analogous Articles. By R. S. Cristiani, Con- 
sulting Chemist and Perfumer, Philadelphia. 8vo. . . $5.00 

DAVIDSON.— A Practical Manual of House Painting, Grain- 
ing, Marbling, and Sign- Writing: 
Containing full information on the processes of House Painting in 
Oil and Distemper, the Formation of Letters and Practice of Sign- 
Writing, the Principles of Decorative Art, a Course of Elementary 
Drawing for House Painters, Writers, etc., and a Collection of Useful 
Receipts. With nine colored illustrations of Woods and Marbles, 
and numerous wood engravings. By Ellis A. Davidson. i2mo. 

tAVIES. — A Treatise on Earthy and Other Minerals and 
Mining : 

' By D. C. Davies, F. G. S., Mining Engineer, etc. Illustrated by 
76 Engravings. i2mo. ....... $5.00 



ro HENRY CAREY BAIRD & CO.'S CATALOGUE. 

DAVIES. — A Treatise on Metalliferous Minerals and Mining: 
By D. C. Davies, F. G. S., Mining Engineer, Examiner of Mines 
Quarries and Collieries. Illustrated by 148 engravings of Geological 
Formations, Mining Operations and Machinery, drawn from the 
practice of all parts of the world. 2d Edition, i2mo., 450 pages $5.00 

DAVIES.— A Treatise on Slate and Slate Quarrying: 
Scientific, Practical and Commercial. By D. C. Da\ies, F. G. ?.. 
Mining Engineer, etc. With numerous illustrations and folditi < 
plates. i2rao. 32.0 ' 

DAVIS. — A Treatise on Steam-Boiler Incrustation and Meth- 
ods for Preventing Corrosion and the Formation of Scale ; 

By Charles T. Davis. Illustrated by 65 engravings. 8vo. $1.50 
DAVIS.— The Manufacture of Paper: 

Being a Description of the various Processes for the Fabrication, 
Coloring and Finishing of every kind of Paper, Including the Dif- 
ferent Raw Materials and the Methods for Determining their Values, 
the Tools, Machines and Practical Details connected with an intelli- 
gent and a profitable prosecution of the art, with special reference to 
the best American Practice. To which are added a History of Pa- 
per, complete Lists of Paper-Making Materials, List of American 
Machines, Tools and Processes used in treating the Raw Materials, 
and in Making, Coloring and Finishing Paper. By Charles T. 
Davis. Illustrated by 156 engravings. 608 pages, 8vo. ;^6.oo 

U AVIS.— The Manufacture of Leather: 

Being a description of all of the Processes for the Tanning, Tawing, 
Currying, Finishing and Dyeing of every kind of Leather ; including 
the various Raw Materials and the Methods for Determining their 
Values ; the Tools, Machines, and all Details of Importance con- 
nected with an Intelligent and Profitable Prosecution of the Art, with 
Special Reference to the Best American Practice. To which are 
added Complete Lists of all American Patents for Materials, Pro- 
cesses, Tools, and Machines for Tanning, Currying, etc. By Charles 
Thomas Davis. Illustrated by 302 engravings and 12 Samples of 
Dyed Leathers. One vol., 8vo., 824 pages . , . $10.00 
DAWIDOWSKY— BRANNT.— A Practical Treatise on the 
Raw Materials and Fabrication of Glue, Gelatine, Gelatine 
Veneers and Foils, Isinglass, Cements, Pastes, Mucilages, 
etc.: 
Eased upon Actual Experience. By F. Dawidowsky, Technical 
Chemist. Translated from the German, with extensive additions, 
including a description of the most Recent American Processes, by 
William T. Brannt, Graduate of the Royal Agricultural College 
of Eldena, Prussia. 35 Engravings. i2mo. . . . ^2.50 
DE GRAFF. — The Geometrical Stair-Builders' Guide: 

Being a Plain Practical System of Hand-Railing, eml)racing all its 
necessary Details, and Geometrically Illustrated by twenty-two Steel 
Eni^ravings; together with the use of the most approved principles 
of Practical Geometry. By SiMO.N De Graff, Architect. 4to. 

S2.SO 



HENRY CAREY BAIRD & CO'.S CATALOGUE. II 



1)E KONINCK— DIETZ.— A Practical Manual of Chemica) 
Analysis and Assaying : 

As applied to the Manufacture of Iron from its Ores, and to Cast Iron, 
Wrought Iron, and Steel, as found in Commerce. By L. L. Di? 
KoNiNCK, Dr. Sc, and E. Dietz, Engineer. Edited with Notes, by 
Robert Mallet, F. R. S., F. S. G'., M. I. C. E., etc. American 
Edition, Edited with Notes and an Appendix on Iron Ores, by A. A. 
Fesquet, Chemist and Engineer. i2mo. . . . ^2.50 

DUNCAN.— Practical Surveyor's Guide: 

Containing the necessary information to make any person of com- 
mon capacity, a finished land surveyor without the aid of a teacher. 
By Andrew Duncan. Illustrated. i2mo. . . . $1.25 

DUPLAIS. — A Treatise on the Manufacture and Distillation 
of Alcoholic Liquors : 
Comprising Accurate and Complete Details in Regard to Alcohol 
from Wine, Molasses, Beets, Grain, Rice, Potatoes, Sorghum, Aspho- 
del, Fruits, etc. ; with the Distillation and Rectification of Brandy. 
Whiskey, Rum, Gin, Swiss Absinthe, etc., the Preparation of Aro- 
matic Waters, Volatile Oils or Essences, Sugars, Syrups, Aromatic 
Tinctures, Liqueurs, Cordial Wines, Effervescing Wines, etc., the 
Ageing of Brandy and the improvement of Spirits, with Copious 
Directions and Tables for Testing and Reducing Spirituous Liquors, 
etc., etc. Translated and Edited from the French of MM. Duplais, 
Aine et Jeune. By M. McKennie, M. D. To which are added the 
United States Internal Revenue Regulations for the Assessment and 
Collection of Taxes on Distilled Spirits. Illustrated by fourteen 
folding plates and several wood engravings. 743 pp. 8vo. $10 00 

DUSSAUCE.— Practical Treatise on the Fabrication of Matches, 
Gun Cotton, and Fulminating Powder. 
By Professor H. Dussauce. i2mo. . . . . $3 00 

DYER AND COLOR-MAKER'S COMPANION: 

Containing upwards of two hundred Receipts for making Colors, on 
the most approved principles, for all the various styles and fabrics now 
in existence; with the Scouring Process, and plain Directions for 
Preparing, Washing-ofF, and Finishing the Goods. i2mo. ^i 25 

EDWARDS. — A Catechism of the Marine Steam-Engine, 

For the use of Engineers, Firemen, and Mechanics. A Practical 
Work for Practical Men. By Emory Edwards, Mechanical Engi- 
neer. Illustrated by sixty-three Engravings, including examples uf 
the most modern Engines. Third edition, thoroughly revised, with 
much additional matter. l2mo. 414 pages . . . $2 00 

EDWARDS. — Modern American Locomotive Engines, 
Their Design, Construction and Management. By Emory Edwards, 
Illustrated i2mo ;^2.oo 

EDWARDS.— The American Steam Engineer: 

Theoretical and Practical, with examples of the latest and most ap- " 
proved American practice in the design and construction of Steam 
Engines and Boilers. For the use of engineers, machinists, boiler- 
tnakers, and engineering students. By Emory Edwards. Fully 
rilustrated, 419 pages. i2mo. .... $2.50 



13. HENRY CAREY BAIRD & CO.'S CATALOGUE. 



EDWARDS. — Modern American Marine Engines, Boiiers, and 
Screw Propellers, 

Their Design and Construction. Showing the Present Practice of 
the most Eminent Engineers and Marine Engine Builders in the 
United States. Illustrated by 30 large and elaborate plates. 4to. ^5.00 
EDWARDS.— The Practical Steam Engineer's Guide 
■ In the Design, Construction, and Management of American Stationary, 
Portable, and Steam Fire-Engines, Steam Pumps, Boilers, Injectors, 
Governors, Indicators, Pistons and Rings, Safety Valves and Steam 
Gauges. For the use of Engineers, Firemen, and Steam Uaers. By 
Emory Edwards. Illustrated by 119 engravings. 420 pages. 
l2mo ■ ^2 50 

EI3SLER.— The Metallurgy of Gold: 

A Practical Treatise on the Metallurgical Treatment of Gold-Bear- 
ing Ores, including the Processes of Concentration and Chlorination, 
and the Assaying, Melting, and Refining of Gold, By M. EiSSLER. 
With 90 Illustrations. l88 pp. i2mo $3 00 

ELDER.— Conversations on the Principal Subjects of Politica.' 
Economy. 
By Dr. William Elder. 8vo $2 5c 

ELDER.— Questions of the Day, 
Economic and Social. By Dr. William Elder. Svd. . $3 00 

ELDER.— Memoir of Henry C. Carey. 
Ey Dr. William Elder. 8vo. cloth 75 

ERNL— Mineralogy Simplified. 

Easy Methods of Determining and Classifying Minerals, including 
Ores, by means of the Blow] ipe, and by Humid Chemical Analysis, 
based on Professor von Kobell's Tables for the Det^mination of 
Minerals, with an Introduction to Modern Chemistry. By Henry 
Erni, A.m., M.D., Professor of Chemistry. Second Edition, rewritten, 
enlarr^ed and improved. i2mo. . . . . 33 oc 

FAIRBAIRN.— The Pnnciples of Mechanism and Machinerj 
of Transmission • 
Comprising the Prmciples of Mechanism, Wheels, and Pullevs. 
Strength and Proportions of Shafts, Coupling of Shafts, and Engag- 
ing and Disengaging Gear. By SiR William Fairbairn, Bait. 
C. E. Beautifully illustrated by over 150 wood-cuts. In one 
▼olume. i2mo ^^2.50 

FLEMING. — Narrow Gauge Railways in America. 

A Sketch of their Rise, Progress, and Success. Valuable Statistics 
as to Grades, Curves, Weight of Rail, Locomotives, Cars, etc. By 
Howard Fleming. Illustrated, 8vo $1 oci 

FORSYTH.— Book of Designs for Headstones, Mural, and 
other Monuments : 
Containing 78 Designs. By James Forsyth. With an Introduction 
py Charles Boutell, M. A. 4 to., cloth . . • ;^5 00 



HENRY CAREY BAIRD & CO.'S CAIALOGUE. 13 

FRANKEL— HUTTER.— A Practical Treatise on the Manu- 
facture of Starch, Glucose, Starch-Sugar, and Dextrine : 

Based on the German of Ladislaus Von Wagner, Professor in the 
Royal Technical High School, Buda-Pest, Hungary, and other 
authorities. By Julius Frankel, Graduate of the Polytechnic 
School of Hanover. Edited by Robert Hutter, Chemist, PracticrV 
Manufacturer of Starch-Sugar. Illustrated by 58 engravings, cover- 
ing every branch of the subject, including examples of the most 
Recent and Best American Machinery. 8vo., 344 pp. . $3.50 

GEE.— The Goldsmith's Handbook : 

Containing full instructions for the Alloying and Working of Gold, 
including the Art of Alloymg, Melting, Reducing, Coloring, Col- 
lecting, and Refining; the Processes of Manipulation, Recovery of 
Waste ; Chemical and Physical Properties of Gold ; with a New 
System of Mixing ite Alloys; Solders, Enamels, and other Useful 
Rules and Recipes. By George E. Gee. i2mo. . . ^i-75 
GEE. — The Silversmith's Handbook : 

Containing full instructions for the Alloying and Working of Silver, 
including the different modes of Refining and Melting the Metal ; its 
Solders; the Preparation of Imitation Alloys; Methods of Manipula- 
tion; Prevention of Waste ; Instructions for Improving and Finishing 
the Surface of the Work ; together with other Useful Information and 
Memoranda. By George E. Gee, Jeweller. Illustrated. i2mo. 

GOTHIC ALBUM FOR CABINET-MAKERS : 

Designs for Gothic Furniture. Twenty-three plates. Oblong $2.00 
GREENWOOD.— Steel and Iron: 

Comprising the Practice and Theory of the Several Methods Pur- 
sued in their Manufacture, and of their Treatment in the Rolling- 
Mills, the Forge, and the Foundry. By William Henry Green- 
wood, F. C. S. Asso. M. I. C. E., M. I. M. E., Associate of the Royal 
School of Mines. With 97 Diagrams, 536 pages. i2mo. . $2.00 

GREGORY.— Mathematics for Practical Men : 

Adapted to the Pursuits of Surveyors, Architects, Mechanics, and 
Civil Engineers. By Olinthus Gregory. 8vo., plates . ^3.00 

GRIER.— Rural Hydraulics : 

A Practical Treatise on Rural Household Water Supply. Giving a 
full description of Springs and Wells, of Pumps and Hydraulic Ram, 
with Instructions in Cistern Building, Laying of Pipes, etc. By W. 
W. Grier. Illustrated 8vo 75 

GRIMSHAW.— Modern Milling: 

Being the substance of two addresses delivered by request, at the 
Franklin Institute, Philadelphia, January 19th and January 27th, 
1 88 1. By Robert Grimshaw, Ph. D. Edited from the Phono- 
graphic Reports. With 28 Illustrations. 8vo. 

GRIMSHAW.— Saws : 
The History, Development, Action, Classification, and Comparison 
of Saws of all kinds. IV^V/i Copious Appendices. Giving the details 



14 HENRY CAREY BAIRD & CO.'S CATALOGUE. 

of Manufacture, Filing, Setting, Gumming, etc. Care and Use ot 
Saws ; Tables of Gauges ; Capacities of Saw-Mills ; List of Saw- 
Patents, and other valuable information. By Robert Grimshaav, 
Second and greatly enlarged edition, with Supplement, and 354 Illus- 
trations. Quarto $\-'^ 

GRIM SHAW. — A Supplement to Grimshaw on Saws : 

Containing additional practical matter, more especially relating to the 
Forms of Saw-Teeth, for special material and conditions, and to the 
Behavior of Saws under particular conditions. I20 Illustrations. By 
Robert Grimshaw. Quarto 

GRIS WOLD.— Railroad Engineer's Pocket Companion for the 
Field : 
Comprising Rules for Calculating Deflection Distances and Angles, 
Tangential Distances and Angles, and all Necessary Tables for En- 
gineers; also the Art of Levelling from Preliminary Survey to the 
Construction of Railroads, intended Expressly for the Young En- 
gineer, together with Numerous Valuable Rules and Examples. By 
W. Griswold. i2mo., tucks ^i-75 

GRUNER.— Studies of Blast Furnace Phenomena: 

By M. L. Gruner, President of the General Council of Mines o! 
France, and lately Professor of Metallurgy at the Ecole des Mines. 
Translated, with the author's sanction, with an Appendix, by L. D. 
B. Gordon, F. R. S. E., F. G. S. 8vo. . . . 32.5G 

Hand-Book of Useful Tables for the Lumberman, Farmer and 
Mechanic : 
Containing Accurate Tables of Logs Reduced to Inch Board Meas- 
ure, Plank, Scantling and Timber Measure; Wages and Rent, by 
Week or Month; Capacity of Granaries, Bins and Cisterns; Land 
Measure, Interest Tables, with Directions for Finding the Interest on 
any sum at 4, 5, 6, 7 and 8 per cent., and many other Useful Tables. 
32 mo., boards. 186 pages .25 

HASERICK.— The Secrets of the Art of Dyeing Wool, Cotton, 
and Linen, 
Including Bleaching and Coloring Wool and Cotton Hosiery and 
Random Yarns. A Treatise based on Economy and Practice. By 
E. C. Haserick. Illustrated by 323 Dyed Patterns of the Yarm 
or Fabrics. 8vo. ........ $12.50 

HATS AND FELTING: 

A Practical Treatise on their Manufacture. By a Practical Hatter. 
Illustrated by Drawings of Machinery, etc. Svo. . . $1-25 

HOFFER. — A Practical Treatise on Caoutchouc and Gutta 

Percha, 

Comprising the Properties of the Raw Materials, and the manner of 

Mixing and Working them ; with the Fabrication of Vulcanized and 

Hard Rubbers, Caoutchouc and Gutta Pescha Compositions, Water. 



HENRY CAREY BAIRD & CO.'S CATALOGUE. i$ 

proof Substances, Elastic Tissues, the Utilization of Waste, etc., etc. 
From the German of Raimund Hoffer. By W. T. Erannt. 
Illustrated i2mo. . $2.50 

HOFMANN.— A Practical Treatise on the Manufacture of 
Paper in all its Branches : 
By Carl Hofmann, Uate Superintendent of Paper-Mills in Germany 
and the United States ; recentl> Manager of the " Public Ledger " 
Paper-Mills, near Elkton, Maryland. Illustrated by no wood en- 
gravings, and five large Folding Plates. 4to., cloth; about 400 
pages $3S-00 

HUGHES. — American Miller and Millwright's Assistant: 
By William Carter Hughes. lamo. .... $1.50 

HULME. — Worked Examination Questions in Plane Geomet- 
rical Drawing : 
For the Use of Candidates for the Royal Military Academy, Wool- 
wich; the Royal Military College, Sandhurst; the Indian Civil En- 
gineering College, Cooper's Hill ; Indian Public Works and Tele- 
graph Departments ; Royal Marine Li^^ht Infantry ; the Oxford and 
Cambridge Local Examinations, etc. By F. Edward Hulme, F, L. 
S., F. S. A., Art-Master Marlborough College. Illustrated by 300 
examples. Small quarto ^2.50 

JERVIS.— Railroad Property: 

A Treatise on the Construction and Management of Railways; 
designed to afford useful knowledge, in the popular style, to the 
holders of this class of property ; as well as Railway Managers, Offi- 
cers, and Agents. By John B. Jervis, late Civil Engineer of the 
Hudson River Railroad, Croton Aqueduct, etc. i2mo., cloth $2.00 

XEENE.— A Hand-Book of Practical Gauging: 

For the Use of Beginners, to which is added a Chapter on Distilla* 
tion, describing the process in operation at the Custom-House for 
asct-rtnining the Strength of Wines. By James B. Keene, of H. M. 
Customs. 8vo. ........ $1-25 

KELLEY. — Speeches, Addresses, and Letters on Industrial and 
Financial Questions : 
By Hon. William D. Kelley, M. C. 544 pages, 8vo. . $3.00 

KELLOGG.— A New Monetary System : 

The only means of Securing the respective Rights of Labor and 
Property, and of Protecting the Public from Financial Revulsions. 
By Edward Kellogg. Revised from his work on " Labor and 
other Capital." With numerous additions from his manuscript. 
Edited by Mary Kellogg Putnam. Fifth edition. To which is 
added a Biographical Sketch of the Author. One volume, i2mo. 

Paper cover ^i.oo 

, Bound in cloth 1.50 

KEMLO.— Watch-Repairer's Hand-Book : 
Being a Complete Guide to the Young Beginner, in Taking Apart, 
Putting Together, and Thoroughly Cleaning the English Lever and 
other yoreign Watches, and all American Watches. By F. Kemlo, 
Practical Watchmaker. With Illustrations. i2mo. . $1.25 



l6 HENRY CAREY BAIRD & CO.'S CATALOGUE. 



KENTISH.— A Treatise on a Box of Instruments, 

And the Slide Rule ; with the Theory of Trigonometry and Loga 
rithms, including Practical Geometry, Surveying, Measuring of Tim- 
ber, Cask and Malt Gauging, Heights, and Distances. By Thomas 
Kentish. In one volume. i2mo. . . . . $i -^ 

KERL.— The Assayer's Manual: 

An Abridged Treatise on the Docimastic Examination of Ores, and 
Furnace and other Artificial Products. By Bruno Kerl, Professor 
in the Royal School of Mines. Translated from the German by 
William T. Brannt. Second American edition, edited with Ex- 
tensive Additions by F. Lynwood Garrison, Member of the 
American Institute of Mining Engineers, etc. Illustrated by 87 en- 
gravings. 8vo $3.00 

KjCK.— Flour Manufacture. 

A Treatise on Milling Science and Practice. By Frederick Kick, 

Imperial Regierungsrath, Professor of Mechanical Technology in the 

imperial German Polytechnic Institute, Prague. Translated from 

the second enlarged and revised edition with supplement by H. H. 

P. PowLES, Assoc. Memb. Institution of Civil Engineers. Illustrated 

with 28 Plates, and 167 Wood-cuts. 367 pages. 8vo. . $ip.oo 

KINGZETT.— The History, Products, and Processes of the 

Alkali Trade : 

Including the most Recent Improvements. By Charles Thomas 

KiNGZETT, Consulting Chemist. With 23 illustrations, 8vo. $2.50 

KINSLEY. — Self-Instructor on Lumber Surveying: 

For the Use of Lumber Manufacturers, Surveyors, and Teachers. 
By Charles Kinsley, Practical Surveyor and Teacher of Surveying. 

i2mo. . . ^2.00 

KIRK.— The Founding of Metals : 

A Practical Treatise on the Melting of Iron, with a Description of the 
Founding of Alloys; also, of all the Metals and Mineral Substances 
used in the Art of Founding. Collected from original sources. By 
Edward Kirk, Practical Foundryman and Chemist. Illustrated. 

Third edition. 8vo. $2.50 

LANDRIN.— A Treatise on Steel: 

Comprising its Theory, Metallurgy, Properties, Practical Working, 
and Use. By M. H. C. Landrin, Jr., Civil Engineer. Translated 
from the French, with Notes, by A. A. Fesquet, Chemist and En- 
gineer. With an Appendix on the Bessemer and the Martin Pro- 
cesses for Manufacturing Steel, from the Report of Abram S. Hewitt 
United States Commissioner to the Universal Exposition, Paris, 1867. 

I2mo $30C 

LARDEN.— A School Course on Heat: 

By W. Larden, M. A. 321 pp. i2mo ;g2.oo 

GARDNER.— The Steam-Engine: 
For the Use of Beginners. By Dr. Lardner. Illustrated. l2mo. 

7J 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 17 

lARKIN.— The Practical Brass and Iron Founder's Guide: 
A Concise Treatise on Brass Founding, Moulding, the Metals and 
their Alloys, etc.; to which are added Recent Improvements in the 
Manufacture of Iron, Steel by the Bessemer Process, etc., etc. By 
James Larkin, late Conductor of the Brass Foundry Department in 
Reany, Neafie & Co.'s Penn Works, Philadelphia. Fifth edition, 
revised, with extensive additions. i2mo. . . . $2.25 

LEROUX.— A Practical Treatise on the Manufacture of 
Worsteds and Carded Yarns : 
Comprising Practical Mechanics, with Rules and Calculations applied 
to Spinning; Sorting, Cleaning, and Scouring Wools; the English 
and French Methods of Comliing, Drawing, and Spinning Worsteds, 
and Manufacturing Carded Yarns. Translated from the French of 
Charles Leroux, Mechanical Engineer and Superintendent of a 
Spinning-Mill, by Horatio Paine, M. D., and A. A. Fesquet, 
Chemist and Engineer. Illustrated by twelve large Plates. To which 
is added an Appendix, containing Extracts from the Reports of the 
International Jury, and of the Artisans selected by the Committee 
appointed by the Council of the Society of Arts, London, on Woolen 
and Worsted Machinery and Fabrics, as exhibited in the Paris Uni- 
versal Exposition, 1867. 8vo. ..... $5.00 

LEFFEL. — The Construction of Mill-Dams : 

Comprising also the Building of Race and Reservoir Embankments 
and Head-Gates, the Measurement of Streams, Gauging of Water 
Supply, etc. By James Leffel & Co. Illustrated by 58 engravings. 
8vo. $2.50 

LESLIE.— Complete Cookery: 
Directions for Cookery in its Various Branches. By Miss Leslie. 
Sixtieth thousand. Thoroughly revised, with the addition of New 
Receipts. In i2mo., cloth ^l-50 

I.IEBER.— Assayer's Guide ; 

Or, Practical Directions to Assayers, Miners, and Smelters, for the 
Tests and Assays, by Heat and by Wet Processes, for the Ores of all 
the principal Metals, of Gold and Silver Coins and Alloys, and of 
Coal, etc. By Oscar M. LiEBER. i2mo. . . . $1.25 

Lockwood's Dictionary of Terms : 

Used in the Practice of Mechanical Engineering, embracing those 
Current in the Drawing Office, Pattern Shop, Foundry, Fitting, Turn- 
ing, Smith's and Boiler Shops, etc., etc., comprising upwards of Six 
Thousand Definitions. Edited by a Foreman Pattern Maker, author 
of " Pattern Making." 417 pp. i2mo. , . . $3.00 

LOVE. — The Art of Dyeing, Cleaning, Scouring, and Finish* 
ing, on the Most Approved English and French Methods; 
Being Practical Instructions in Dyeing Silks, Woolens, and Cottons, 
Feathers, Chips, Straw, etc. Scouring and Cleaning Bed and Win- 
dow Curtains, Carpets, Rugs, etc. trench and English Cleaning, 
any Color or Fabric of Silk, Satin, or Damask. By Thomas Love, 
a Working^ Dyer and Scourer- Second American Edition, to which 



tg HENRY CAREY BAIRD & CO.'S CATALOGUE. 

are added General Instructions for the use of Aniline Colors. 8vo. 

343 pages 

LUKIN. — Amongst Machines: 

Embracing Descriptions of the various Mechanical Appliances used 
in the Manufacture of Wood, Metai, and other Substances. J2mo. 

^1-75 
iUKIN.— The Boy Engineers : 

, What They Did, and How They Did It. With 30 plates. i8mo. 

LUKIN.— The Young Mechanic : 

Practical Carpentry. Containing Directions for the Use of all kinds 
of Tools, and for Construction of Sieam- Engines and Mechanical 
Models, including the Art of Turning in Wood and Meial. By John 
LuKiN, Author of "The Lathe and Its Uses," etc. Illustrated. 
l2mo ^1-75 

MAIN and BROWN.— Questions on Subjects Connected with 

the Marine Steam- Engine; 

And Examination Papers; with Hints for their Solution. By 

Thomas J. Main, Professor of Mathematics, Royal Naval College, 

and Thomas Brown, Chief Engineer, R. N. i2mo., cloth . $1.50 

MAIN and BROWN. — The Indicator and Dynamometer: 
With their Practical Applications to the Steam-Engine. By Thomas 
J. Main, M. A. F. R., Ass't S. Professor Royal Naval College, 
Portsmouth, and Thomas Brown, Assoc. Inst. C. E., Chief Engineer 
R. N., attached to the R. N. College. Illustrated, 8vo. . 31.50 

MAIN and BROWN.— The Marine Steam-Engine. 
By Thomas J. Main, F. R. Ass't S. Mathematical Professor at the 
Royal Naval College, Portsmouth, and Thomas Brown, Assoc. 
Inst. C. E., Chief Engineer R. N, Attached to the Royal Naval 
College. With numerous illustrations. 8vo. . . . SS 00 

MARTIN.— Screw-Cutting Tables, for the Use of Mechanical 
Engineers : 
Showing the Proper Arrangement of Wheels for Cutting the Threads 
of Screws of any Required Pitch ; with a Table for Making the Uni- 
versal Gas-Pipe Thread and Taps. By W. A. Martin, Engineer. 
8vo. , 50 

MICHELL.— Mine Drainage: 
Being a Complete and Practical Treatise on Direct-Acting Under- 
jyround Steam Pumping Machinery. With a Description of a large 
number of the best known Engines, their General Utility and the 
Special Sphere of their Action, the Mode of their Application, /ind 
their Merits compared with other Pumping Machinery. By Stephkn 
MiCHELL. Illustrated by 137 engravings. Svo., 277 pages . $6.00 

MOLESWORTH.— Pocket-Book of Useful Formulae and 

, Memoranda for Civil and Mechanical Engineers. 
By Guilford L. Molesworth, Member of the Institution of Civil 
Engineers, Chief Resident Engineer of the Ceylon Railway. Full- 
Jaaund in Pocket-book form ;gl.oo 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 19 

MOORE. — The Universal Assistant and the Complete Me- 
chanic : 

Containing over one million Industrial Facts, Calculations, Receipts, 
Processes, Trades Secrets, Rules, Business Forms, Legal Items, Etc., 
in every occupation, from the Household to the Manufactory. By 
R. Moore. Illustrated by 500 Engravings. i2mo. . ^2.50 

MORRIS, — Easy Rules for the Measurement of Earthworks : 
By means of the Prismoidal Formula. Illustrated with Numerous 
Wood-Cuts, Problems, and Examples, and concluded by an Exten- 
sive Table for finding the Solidity in cubic yards from Mean Areas. 
The whole being adapted for convenient use by Engineers, Surveyors, 
Contractors, and others needing Correct Measurements of Earthwork. 

By Elwood Morris, C. E. 8vo $i-5o 

-MORTON. — The System of Calculating Diameter, Circumfer» 
•^ ence, Area, and Squaring the Circle : 

Together with Interest and Miscellaneous Tables, and other informa- 
tion. By James Morton. Second Edition, enlarged, with the 
Metric System. i2mo ^i.oo 

NAPIER.— Manual of Electro-Metallurgy: 

Including the Application of the Art to Manufacturing Processes. 
By James Napier. Fourth American, from the Fourth London 
edition, revised and enlarged. Illustrated by engravings. 8vo. 

NAPIER. — A System of Chemistry Applied to Dyeing. 

By James Napier, F. C. S. A New and Thoroughly Revised Edi- 
tion. Completely brought up to the present state of the Science, 
nicluding the Chemistry of Coal Tar Colors, by A. A. Fesquet, 
Chemist and Engineer. With an Appendix on Dyeing and Caaco 
Printing, as shown at the Universal Exposition, Paris, 1867. Illus- 
trated. 8vo. 422 pages . . . ... . . $5.00 

NEVILLE.— Hydraulic Tables, Coefficients, and Formulae, for 
finding the Discharge of Water from Orifices, Notches, 
Weirs, Pipes, and Rivers : 
Third Edition, with Additions, consisting of New Formulae for the 
Discharge from Tidal and Flood Sluices and Siphons; general infor- 
mation on Rainfall, Catchment-Basins, Drainage, Sewerage, Waier 
Supply for Towns and Mill Power. By Tohn Neville, C. E. M. R. 
I. A. ; Fellow of the Royal Geological Society of Ireland. Thick 
I2mo 15.50 

NEWBERY.— Gleanings from Ornamental Art of every 
style : 
Drawn from Examples in the British, South Kensington, Indian, 
Crystal Palace, and other Museums, the Exhibitions of 185 1 and 
1862, and the best English and Foreign works. In a series of 100 
exquisitely drawn Plates, containing many hundred examples. By 
Robert Newbery. 4to. ...... ;^ 12.50 

NICHOLLS. —The Theoretical and Practical Boiler-Maker and 
Engineer's Reference Book: 
Containing a variety of Useful Information for Employers of Labor. 
Foremen and Workin^j Boiler-Makers, Iron, Copper, and Tinsmith* 



tto HENRY CAREY BAIRD & CO/S CATALOGUE. 

Draughtsmen, Engineers, the General Steam-using Public, and for the 
Use (jf Science Schools and Classes. By Samuel Nicholls. Illus. 
trated by sixteen plaies, i2mo. ..... ^^2.50 

NICHOLSON.— A Manual of the Art of Bookbinding: 

Containing full instruciions in the different Branches of Forwarding, 
Gilding, and Finishing. Also, the Art of Marbling Book-edges and 
Paper. By jA^JiiS B. NICHOLSON, Illustrated. i2mo., cloth $2.25 

NICOLLS.— The Railway Builder: 

A Hand-Book for Estimating the Probable Cost of American Rail- 
way Construction and Equipment. By William J. Nicolls, Civil 
Engineer. Illusti-ated, full bound, pocket-book form . $2.00 

NORMANDY.— The Commercial Handbook of Chemical An. 
alysis : 
Or Practical Instructions for the Determinntion of the Intrinsic 01 
Commercial Value of Substances used in Manufactures, in Trades, 
and in the Arts. By A. Normandy. New Edition, Enlarged, and 
to a great extent rewritten. By Henry M. Noad, Ph.D., F.R.S., 
thick i2mo $S-OC- 

NORRIS. — A Handbook for Locomotive Engineers and Ma- 
chinists : 
Comprising the Proportions and Calculations for Constructing Loco- 
motives; Manner of Setting Valves; Tables cf Squares, Cubes, Areas, 
etc., etc. By Septimus Norris, M. E. New edition. Illustrated, 
I2mo. j^i.50 

NYSTROM. — A New Treatise on Elements of Mechanics : 
Establishing Strict Precision in the Meaning of Dynamical Terms-, 
accoirpanied with an Appendix on Duodenal Arithmetic and Me 
trology. By John W. Nystrom, C. E. Illustrated. 8vo. $2.og 

NYSTROM.— On Technological Education and the Construc- 
tion of Ships and Screw Propellers : 
For Naval and Marine Engineers. By John W. Nystrom, late 
Acting Chief Engineer, U. S. N. Second edition, revised, with addi- 
tional matter. Illustrated by seven engravings. i2mo. . $1.$^ 

O'NEILL. — A Dictionary of Dyeing and Calico Printing: 

Containing a brief account of ail >he Substances and Processes in 
use in the Art of Dyeing and Printing Textile Fabrics ; with Practical 
Receipts and Scientific Information, By Charles O'Neill, Analy- 
tical Chemist. To which is added an Essay on Coal Tar Colors and 
their application lo Dyeing and Calico Printing. By A. A. Fesquet, 
Chemist and Engineer. With an appendix on Dyeing and Calico 
Printing, as shown at the Universal Exposition, Paris, 1867- 8vo., 
491 pages $5.00 

ORTON. — Underground Treasures-. 

How and Where to Find Them. A Key for the Ready Determination 
of all the Useful Minerals within the United Slates. By James 
Orton, A.m., Late Professor of Natural History in Vassar College, 
N. Y.; Cor. Mem. of the Academy of Natural Sciences, Philadelphia, 
and of the Lyceum of Natural History, New York ; author of the 
** Andes and the Amazon," etc. A New Edition, with Additions, 
lilusirated - . - Jpi.50 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



OSBORN.— The Metallurgy of Iron and Steel: 

Theoretical and Practical in all its Branches; with special rc^rence 
to American Materials and Processes. By H. S. O-hoKN, LL. D., 
Professor of Mining and ^^letallurgy in Lafayette College, Easton, 
Pennsylvania, Illustrated by numenms large folding plates and 
wood-engravings, 8vo. ...... $25.00 

OSBORN. — A Practical Manual of Minerals, Mines and Min- 
ing: 
Comprising the Physical Properties, Geologic Positions, Local Occur- 
rence and Associations of the Useful Minerals; their Methods of 
Chemical Analysis and Assay : together with Various Systems of 
Excavating and Timbering, Brick and Masonry Work, during Driv- 
ing, Lining, Bracing and other Ojierations, etc. By Prof. H. S. 
OsBORN, LL. D., Author of the " Metallurgy of Iron and Steel." 
Illustrated by 17 1 engravings from original drawings. 8vo. j^.50 

OVERMAN.— The Manufacture of Steel : 

Containing the Practice and Principles of Working and Making Steel. 
A Handbook for Blacksmiths and W^orker^ in Steel and Iron, Wagon 
Makers, Die Sinkers, Cutlers, and Manufacturers of Files and Hard- 
ware, of Steel and Iron, and for Men of Science and Art. By 
Frederick Overman, Mining Engineer, Author of the " Manu- 
facture of Iron," etc. A new, enlarged, and revised Edition. By 
A. A. Fesquet, Chemist and Engineer. l2mo. . . $1.50 

OVERMAN.— The Moulder's and Founder's Pocket Guide : 
A Treatise on Moulding and Founding in Green-sand, Dr}'-sand,Loam, 
and Cement; the Moulding of Machine Frames, Mill-gear, Hollow- 
ware, Ornaments, Trinkets, Bells, and Statues; Description of Moulds 
for Iron, Bronze, Brass, and other Melals ; Plaster of Paris, Sulphur, 
Wax, etc. ; the Construction of Melting Furnaces, the Melting and 
Founding of Metals ; the Composition of Alloys and their Nature, 
etc., etc. By Frederick Overman, M. E. A new Edition, to 
which is added a Supj^iement on Statuary and Ornamental Moulding, 
Ordnance, Malleable Iron Castings, etc. By A. A. Fesquet, Chem- 
ist and Engineer. Illustrated by 44 engravings. i2mo. . $2.00 

PAINTER, GILDER, AND VARNISHER'S COMPANION; 
Containing Rules and Regulations in everything relating to the ArtS 
of Painting, Gilding, Varnishing, Giass-Slaining, (jrraining, Marbling, 
Sign- Writing, Gilding on Glass, and Coach Painting and Varnishing; 
Tests for the Deteciion of Adulterations in Oils, Colors, etc.; and a 
Statement of the Diseases to which Painters are peculiarly liable, with 
the Simplest and Best Remedies. Sixteenth Edition. Revised, with 
an Appendix. Containing Colors and Coloring — Theoretical and 
Practical. Comprising descriptions of a great variety of Additional 
Pigments, their Qualities and Uses, to which are added, Dryers, and 
Modes and Operations of Painting, etc. Together with Chevreui's 
Principles of Harmony and Contrast of Colors. l2mo. Cloth $1.50 

PALLETT.— The Miller's, Millwright's, and Engineer's Guide. 
By Henry Pallett. Illustrated. i2mo. . . , $2.00 



22 HENRY CAREY BAIRD & CO.'S CATALOGUE. 

PERCY.— The Manufacture of Russian Sheet-Iron. 

By John Percy, M. D., F. R, S., Lecturer on Metallurgy at the 
Royal School of Mines, and to The Advance Class of Artillery 
Officers at the Royal Artillery Institution, Woolwich ; Author of 
" Metallurgy," With Illustrations. 8vo., paper . . 50 cts 

PERKINS.— Gas and Ventilation : 

Practical Treatise on Gas and Ventilation. With Special Relation 
to Illuminaiing, Heating, and Cooking by Gas. Including Scientific 
Helps to Engineer-students and others. With Illustrated Diagrams. 
By E. E. Perkins. i2mo., cloth ^1.21; 

PERKINS AND STOWE.— A New Guide to the Sheet-iron 
and Boiler Plate Roller : 
Containing a Series of Tables showing the Weight of Slabs and Piles 
to Produce Boiler Plates, and of the Weight of Piles and the Sizes of 
Bars to produce Sheet-iron ; the Thickness of the Bar Gaugt 
in decimals; the Weight per foot, and the Thickness on the Bar or 
Wire Gauge of the fractional parts of an inch; the Weight per 
sheet, and the Thickness on the Wire Gauge of Sheet-iron of various 
dimensions to weigh 112 lbs. per bundle; and the conversion of 
Short Weight into Long Weight, and Long W^eight into Short. 
Estimated and collected by G. H. Perkins and J. G. Stowe. ^2.53 

POWELI CHANCE— HARRIS.— The Principles of Glass 

Making. 
By Harry J. Powell, B. A. Together with Treatises on Crown and 
Sheet Glass; by Henry Chance, M. A. And Plate Glass, by H. 
G. Harris, Asso. M. Inst. C. E. Illustrated i8mo. . $1.50 

PROCTOR.— A Pocket-Book of Useful Tables and Formulae 
for Marine Engineers : 
By Frank Proctor. Second Edition, Revised and Enlarged. 
P'ull -bound pocket-book form ...... $1.50 

REGNAULT.— Elements of Chemistry: 

By M. V. Regnault. Translated from the French by T. Forrest 
Betton, M. D., aitid edited, with Notes, by James C. Booth, Melter 
and Refiner U. S. Mint, and William L. Faber, Metallurgist and 
Mining Engineer. Illustrated by nearly 700 wood-engravings. Com- 
prising nearly 1,500 pages. In two volumes, 8vo., cloth . j^7.50 

RICHARDS.— Aluminium : 

Its History, Occurrence, Properties, Metallurgy and Applications, 
including its Alloys. By Joseph W. Richards, A. C, Chemist and 
Practical Metallurgist, Member of the Deutsche Chemische Gesell 
schift. Illustrated by 16 engravings. 12 mo. 346 pages ^250 

RIFFAULT, VERGNAUD, and TOUSSAINT.— A Practical 
Treatise on the Manufacture of Colors for Painting : 
Conipri->ing the Origm, Definition, and Classification of Colors: the 
Treatnient of the Raw Materials; the best P^ormulro and the Newest 
Processes for the Preparation of every description of Pigment, and 
the Necessary Apparatus and Directions for its Use; Dryers; the 
Testing, Application, and Qualities of Paints, etc., etc. By MM. 
R^fkault, Vergnaud, and Toussaint. Revised and Edited by M. 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 23 

» 

F. Malepeyre. Translated from the French, by A. A. Fesquet; 
Chemist and Engineer, Illustrated by Eighty engravings. In one 
vol.. 8vo., 659 pages ....... ^7*5^ 

ROPER. — A Catechism of High- Pressure, or Non-Condensing 
Steam-Engines : 
Including the Modelling, Constructing, and Management of Steam- 
Engines and Steam Boilers. With valuable illustrations. By Ste- 
phen Roper. Engineer. Sixteenth edition, revised and enlarged. 
l8mo., tucks, gilt edge ....... ^2.00 

ROPER.— Engineer's Handy-Book: 

Containing a full Explanation of the Steam-Engine Indicator, and its 
Use and Advantages to Engineers and Steam Users. With Formulae 
for Estimating the Power of all Classes of Steam-Engines ; also. 
Facts, Figures, Questions, and Tables for Engineers w^ho wish to 
qualify themselves for the United States Navy, the Revenue Service, 
the Mercantile Marine, or to take charge of the Better Class of Sta- 
tionary Steam-Engines. Sixth edition. l6mo.. 690 pages, tucks, 
gilt edge $3.50 

ROPER. — Hand-Book of Land and Marine Engines : 

Including the Modelling, Construction, Running, and Management 
of Lanr" and Marine Engines and Boilers. With illustrations. By 
Stephen Roper, Engineer. Sixth edition. i2mo.,tixks, gilt edge. 

ROPER.— Hand-Book of the Locomotive : 

Including the Construction of Engines and Boilers, and the Construc- 
tion, Management, and Running of Locomotives. By Stephen 
Roper, Eleventh edition. i8mo., tucks, gilt edge , ^2.50 

ROPER.— Hand-Book of Modern Steam Fire-Engines. 

With illustrations. By Stephen Roper, Engineer. Fourth edition, 
i2mo., tucks, gilt edge ....... ^3.50 

ROPER. — Questions and Answers for Engineers. 

This little book contains all the Questions that Engineers will be 
asked when undergoing an Examination for the purpose of procuring 
Licenses, and they are so plain that any Engineer or Fireman of or 
dinary intelligence may commit them to memory in a short time. By 
Stephen Roper, Engineer. Third edition . . . $3.00 

ROPER,— Use and Abuse of the Steam Boiler. 
By Stephen Roper, Engineer. Eighth edition, with illustrations. 
i8mo., tucks, gilt edge ^2.00 

ROSE.— The Complete Practical Machinist : 

Embracing Lathe Work, Vise Work, Drills and Drilling, Taps and 
Dies, Hardening and Tempering, the Making and Use of Tools, 
Tool Grinding, Marking out Work, etc. By JosHUA Rose. Illus- 
trated by 356 engravings. Thirteenth edition, thoroughly revised 
and in great part rewritten. In one vol., i2mo., 439 pages ^2.50 

ROSE.— Mechanical Drawing Self-Taught: 
Comprising Instructions in the Selection and Preparation of Drawing 
Instruments, Elementary Instruction in Practical Mechanical Draw- 



24 HENRY CAREY BAIRD & CO.'S CATALOGUE. 

• ■ V 

ing, together with Examples in Simple Geometry and Elementary 
Mechanism, including Screw Threads, Gear Wheels, jNIechanical 
Motions, Engines and Boilers. By JosHUA Rose, M. E. Illustrated 
by 330 engravings. 8vo., 313 pages .... $4.00 

ROSE.— The Slide- Valve Practically Explained: 

Embracing simple and complete Practical Demonstrations of the 
operation of each element in a Slide-valve Movement, and illustrat- 
ing the effects of Variations in their Proportions by examples care- 
fully selected from the most recent and successful practice. By 
Joshua Rose, M. E. Illustrated by 35 engravings . Si.co 

ROSS. — The Blowpipe in Chemistry, Mineralogy and Geology; 
Containing all Known Methods of Anhydrous Analysis, many \Vork- 
ing Examples, and Instructions for Making Apparatus. By LiEUT.- 
CoLONEL W. A. Ross, R. A., F. G. S. With 120 Illustrations. 
i2mo 32.00 

SHAW.— Civil Architecture : 

Being a Complete Theoretical and Practical System of Building, con- 
taining the Fundamental Principles of the Art. By Edward Shaw, 
Architect. To which is added a Treatise on Gothic Architecture, etc. 
By Thomas W. Sili.oway and George M. Harding, Architects. 
The whole illustrated by 102 quarto plates finely engraved on copper. 
Eleventh edition. 4to. ....... $10.00 

SHUNK. — A Practical Treatise on Railway Curves and Loca- 
tion, for Young Engineers. 
By W. F. Shunk, C. E. i2mo. Full bound pocket-book form $2.00 

SLATER.— The Manual of Colors and Dye Wares. 
By J. W. Slater. i2mo S3. 75 

SLOAN. — American Houses : 

A variety of Original Designs for Rural Buildings. Illustrated by 
26 colored engravings, with descriptive references. By Samuel 
Sloan, Architect. 8vo. ...... Si. 50 

SLOAN. — Homestead Architecture: 

Containing Forty Designs for Villas, Cottages, and Farm-houses, with 
Essays on Style, Construction, Landscape Gardening, Furniture, etc., 
etc. Illustrated by upwards of 200 engravings. By Samuel Sloan, 

Architect. 8vo $3-50 

SLOANE.— Home Experiments in Science. 

By T. O'CoNOR Sloane, E. M., A.M., Ph.D. Illustrated by 91 
engravings, i2mo. ....... 3 1.50 

SMEATON.— Builder's Pocket-Companion : 

Containing the Elements of Building, Surveying, and Architecture; 

with Practical Rules and Instructions connected with the sul)ject. 

By A. C. Smeaton, Civil Engineer, etc. i2mo. . . Si. 50 
SMITH.— A Manual of Political Economy. 

By E. Pkshine Smith. A New Edition, to which is added a full 

Index. i2mo. $1.25 



KENRY CAREY BaIRD & CO.'S CATALOGUE. 25 

SMITH— Parks and Pleasure-Grounds : 

Or Praciical Notes on Country Residences, Villas, Public Parks, and 
Gardens. By Charles H. J. Smith, Landscape Gardener and 
Garden Architect, etc., etc. i2mo. .... ^2.00 

SMITH.— The Dyer's Instructor: 

Comprising Practical Instructions in the Art of Dyeing Silk, Cotton, 
Wool, and Worsted, and Woolen Goods ; containing nearly 800 
Receipts. To which is added a Treatise on the Art of Padding; and 
the Printing of Silk Warps, Skeins, and Handkerchiefs, and the 
various Mordants and Colors for the different styles of such work. 
By David Smith, Pattern Dyer. i2mo. . . . ^3.00 

SMYTH. — A Rudimentary Treatise on Coal and Coal-Mining. 
By Warrington W. Smyth, M. A., F. R. G., President R. G. S. 
of Cornwall, Fifth edition, revised and corrected. AVith numer- 
ous illustrations. i2mo. ...... ^1.75 

SNIVELY. — A Treatise on the Manufacture of Perfumes and 
Kindred Toilet Articles. 
By John H. Snively, Phr. D., Professor of Analytical Chemistry in 
the Tennessee College of Pharmacy. 8vo. 

SNIVELY.— Tables for Systematic Qualitative Chemical Anal- 
ysis. 
By John H. Snively, Phr. D. 8vo. .... ;^i.oo 

SNIVELY.— The Elements of Systematic Qualitative Chemical 
Analysis : 
A Hand-book for Beginners. By John H. Snively, Phr. D. i6mo, 

^2.00 

STEWART.— The American System : 

Speeches on the Tariff Question, and on Internal Improvements, 
principally delivered in the House of 'Representatives of the United 
States. By Andrew Stewart, late M. C. from Pennsylvania. 
With a Portrait, and a Biographical Sketch. 8vo. . . $3.00 

STOKES. — The Cabinet-Maker and Upholsterer's Companion; 
Comprising the Art of Drawing, as applicable to Cabinet Work; 
Veneering, Inlaying, and Buhl-Work; the Art of Dyeing and Stain- 
ing Wood, Ivory, Bone, Tortoise-Shell, etc. Directions for Lacker- 
ing, Japanning, and Varnishing; to make French Polish, Glues, 
Cements, and Compositions; with numerous Receipts, useful to work- 
men generally. By J. Stokes, Illustrated. A New Edition, with 
an Appendix upon French Polishing, Staining, Imitating, Varnishing, 
etc., etc. i2mo. . . . . . . . $1.25 

STRENGTH AND OTHER PROPERTIES OF METALS; 
Reports of Experiments on the Strength and other Projjertieb of 
Metals for Cannon. With a Description of the Machines for Testing 
Metals, and of the Classification of Cannon in service. By Officers 
of the Ordnance Department, U. S. ilrmy. By authority of the Secre* 
taryofWar. Illustrated by 25 large steel plates. Quarto . ;$io.oc 

SULLIVAN.— Protection to Native Industry. 

By Sir Edward Sullivan, Baronet, author of "Ten Chapters on 
Social Reforms." Svo i^i-50 



«6 HENRY CAREY BAIRr» & CO.'S CATALOGUE. 



SYME. — Outlines of an Industrial Science. 

By David Syme. i2mo. . . ... $2.oa 

TABLES SHOWING THE WEIGHT OF ROUND, 
SQUARE, AND FLAT BAR IRON, STEEL, ETC., 

By Measurement. Cloih ...... 6^ 

TAYLOR.— Statistics of Coal : 

Including Mineral Bituminous Substances employed in Arts and 
Manuiaciures ; with their Geographical, Geological, and Commercial 
Distribution and Amount of Production and Consumption on the 
American Continent. With Incidental Statistics of the Iron Manu- 
facture. By R. C. Taylor. Second edition, revised by S. S. Halde- 
MAN. Illustrated by five Maps and many wood engravings. 8vo., 
cloth . . ^lo.oo 

TEMPLETON.— The Practical Examinator on Steam and the 
Steam -Engine: 
With Instructive References relative thereto, arranged for the Use of 
Engineers, Students, and others. By William Templeton, En- 
gineer. i2mo. ........ ^1.25 

THAUSING.— The Theory and Practice of the Preparation of 
Malt and the Fabrication of Beer: 
With especial reference to the Vienna Process of Brewing. Elab- 
orated from personal experience by JuLius E. Thausing, Professor 
at the School for Brewers, and at the Agricultural Institute, Modling, 
near Vienna. Translated from the German by WiLLTAM T. Brannt, 
Thoroughly and elaborately edited, with much American matter, and 
according to the latest and most Scientific Practice, by A. Schwarz 
and Dr. A. H. Bauer. Illustrated by 140 Engravings. 8vo., 81 s 
pages $10.00 

THOMAS.— The Modern Practice of Photography: 
By R. W. Thomas, F. C. S. 8vo 75 

THOMPSON.— Political Economy. With Especial Reference 
to the Industrial History cff Nations : 
By Robert E. Thompson, M. A., Professor of Social Science in the 
University of Pennsylvania. l2mo. .... $1.50 

THOMSON.— Freight Charges Calculator: 

By Andrew Thomson, Freight Agent. 24mo. . . $1.25 

TURNER'S (THE) COMPANION: 

Containing Instructions in Concentric, Elliptic, and Eccentric Turn- 
i'lg; also various Plates of Chucks, Tools, and Instruments; and 
Directions for using the Eccentric Cutler, Drill, Vertical Cutter, and 
Circular Rest; with Patterns and Instructions for working them 
i2mo. . . . . . . . , . . 51 25 

TURNING: Specimens of Fancy Turning Executed on the 

Hand or Foot- Lathe : 

With Geometric, Oval, and Eccentric Chucks, and Elliptical Cutting 

Frame. By an Amateur. Illustrated by 30 exquisite Photogrr.phs. 

4to. $3.00 

URBIN— BRULL.— A Practical Guide for Puddling Iron and 
Steel. 
By El). Urbin, Engineer of Arts and Manufactures. A Prize Essay. 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 27 

read before the Association of Engineers, Graduate of the School of 
Mines, of Liege, Belgium, at the Meeting of 1865-6. To which is 
added A Comparison of the Resisting Properties of Iron and 
Steel. By A. Brull. Translated from the French by A. A. Fes- 
QUET, Chemist and Engineer. 8vo. . . . . ^i.oo 

VA1L.K. — Galvanized- Iron Cornice-Worker's Manual: 

Containing Instructions in Laying out the Different Mitres, and 
Making Patterns for all kinds of Plain and Circular Work. Also, 
Tables of Weights, Areas and Circumferences of Circles, and olher 
Matter calculated to Benefit the Trade. By Charles A. Vaile. 
Illustrated by twenty-one plates. 4to. . . . . ^5.00 

VILLE. — On Artificial Manures: 

Their Chemical Selection and Scientific Application to Agriculture. 
A series of Lectures given at the Experimental Farm at Vincennes, 
during 1867 and 1874-75. By M. Georges Ville. Translated and 
Edited by WiLLlAM Crookes, F. R. S. Illustrated by thirty-one 
engravings. 8vo., 450 pages ...... ^6.00 

7ILLE. — The School of Chemical Manures : 
Or, Elementary Principles in the Use of Fertilizing Agents. From 
the French of M. Geo. Ville, by A. A. Fesquet, Chemist and En- 
gineer. With Illustrations. i2mo. .... j$i-25 

VOGDES. — The Architect's and Builder's Pocket- CompanioiTi 
and Price-Book : 
Consisting of a Short but Comprehensive Epitome of Decimals, Duo- 
decimals, Geometry and Mensuration ; with Tables of United States 
Measures, Sizes, Weights, Strengths, etc., of Iron, Wood, Stone, 
Brick, Cement and Concretes, Quantities of Materials in given Sizes 
and Dimensions of Wood, Brick and Stone; and full and complete 
Bills of Prices for Carpenter's Work and Painting ; also. Rules for 
Computing and Valuing Brick and Brick Work, Stone Work, Paint- 
ing, Plastering, with a Vocabulary of Technical Terms, etc. By 
Frank \V. Vogdes, Architect, Indianapolis, Ind. Enlarged, revised, 
and corrected. In one volume, 368 pages, full-bound, pocket-book 
form, gilt edges ........ $2.00 

Cloth . . 1.50 

WAHL. — Galvanoplastic Manipulations : 

A Practical Guide tor the Gold and Silver Electroplater and me Gal- 
vanoplastic Operator. Comprising the Electro-Deposition of all 
Metals by means of the Battery and the Dynamo-Electric Machine, 
as well as the most approved Processes of Deposition by Simple Im- 
mersion, with Descriptions of Apparatus, Chemical Products employed 
in the Art, etc. Based largely on the " Manipulations Hydroplas- 
tiques" of Alfred Roseleur. By William H. Wahl, Ph. D. 
(Heid), Secretary of the Franklin Institute. Illustrated by 189 en- 
gravings. 8vo., 656 pages ^7-5*^ ■ 

WALTON. — Coal-Mining Described and Illustrated: 

By Thomas H. Walton, Mining Engineer. Illustrated by 24 larg- 
and elaborate Plates, after Actual Workings and Apparatus. $5.00 



28 HENRY CAREY BAIRD & CO.'S CATALOGUE. 



WARE.— The Sugar Beet. 

\ Including a History of the Beet Sugar Industry in Europe, Varietie* 
of the Sugar Beet, Examination, Soils, Tillage, Seeds and Sowing, 
Yield and Cost of Cultivation, Harvesting, Transpuitatioii, Conserva- 
tion, Feeding Qualities of the Beet and of the Pulp, etc. By Lewis 
S. Ware, C. E., M. E. Illustrated by ninety engravings. 8vo, 

$4.00 

WARN.— The Sheet-Metal Worker's Instructor: 

P'or Zinc, Sheet- Iron, Copper, and Tin- Plate Workers, etc. Contain^ 
ing a selection of Geometrical Problems ; also. Practical and Simple 
Rules for Describing the various Patterns required in the different 
branches of the above Trades. By Reuben H. Warn, Praciicai 
Tin-Plate Worker, To which is added an Appendix, containing 
Instructions for Boiler-Making, Mensuration of Surfaces and Solids, 
Rules for Calculating the Weights of different Figures of Iron and 
Steel, Tables of the Weights of Iron, Steel, etc. Illustrated by thirty- 
two Plates and thirty-seven Wood Engravings. 8vo. . ^3.00 

WARNER.— New Theorems, Tables, and Diagrams, for the 
Computation of Earth-work : 

Designed for the use of Engineers in Preliminary and Final Estimates, 
of Students in Engineering, and of Contractors and other non-profes- 
sional Computers. In two parts, with an Appendix. Part I. A Prac- 
tical Treatise ; Part II. A Theoretical Treatise, and the Appendix. 
Containing Notes to the Rules and Examples of Part I.; Explana- 
tions of the Construction of Scales, Tables, and Diagrams, and a 
Treatise upon Equivalent Square Bases and Equivalent Level Heights. 
The whole illustrated by numerous original engravings, comprising 
explanatory cuts for Definitions and Problems, Stereometric Scales 
and Diagrams, and a series of Lithographic Drawings from Models . 
Showing all the Combinations of Solid Forms which occur in Railroad 
Excavations and Embankments. By John Warner, A. M., Mining 
and Mechanical Engineer. Illustrated by 14 Plates. A new, revised 
and improved edition. 8vo. ...... $4.00 

WATSON.— A Manual of the Hand-Lathe : 

Comprising Concise Directions for Working Metals of all kinds, 
Ivory, Bone and Precious Woods; Dyeing, Coloring, and French 
Polishing; Inlaying by Veneers, and various methods practised to 
produce Elaborate work with Dispatch, and at Small Expense. By 
Egbert P. Watson, Author of " The Modern Practice of American 
Machinists and Engineers." Illustrated by 78 engravings. ^1.50 

WATSON. — The Modern Practice of American Machinists and 
Engineers : 
Including the Construction, Application, and Use of Drills. Lathe 
Tools, Cutters for Boring Cylinders, and Hollow-work generally, with 
the most Economical Speed for the same ; the Results verified by 
Actual Practice at the Lathe, the Vise, and on the Floor. Togetner 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 29 

with Workshop Management, Economy of Manufacture, the Steam 
Engine, Boiltrb, Gears, Belling, etc., etc. By EGBERT P. Watson 
Illustrated by eighty-six engravings. i2mo. . . . *2.5C 

?\rATSON.— The Theory and Practice of the Art of Weaving 
by Hand and Power : 
With Calculations and Tables for the Use of those connected with the 
Trade. By John Watson, Manufacturer and Practical Machine- 
Maker. Illustrated by large Drawings of the best Power Looms. 
8vo. . . . • ^7.50 

WATT.— The Art of Soap Making: 
A Practical Hand-book of the Manufaciuie of Hard and Soft Soaps, 
Toilet Soaps, etc., including many New Processes, and a Chapter on 
the Recovery of Glycerine from Waste Leys. By Alexander 
Watt. 111. i2mo. ^300 

WEATHERLY.— Treatise on the Art of Boiling Sugar, Crys- 
tallizing, Lozenge-making, Comfits, Gum Goods, 
And other processes for Confectionery, etc., in which are explained, 
in an easy and familiar manner, the various Methods of Manufactur- 
ing every Description of Raw and Refined Sugar Goods, as sold by 
Confectioners and others. i2mo $i-S^ 

WIGHTWICK.— Hmts to Young Architects: 

Compnsmg Advice to those who, while yet at school, are destined 
to the Profession; to such as, having passed their pupilage, are about 
to travel ; and to those who, having completed their education, are 
about to practise. Together with a Model Specification involving a 
great variety of instructive and suggestive matter. By GEORGE 
W'GHTWICK, Architect. A new edition, revised and considerably 
enlarged; comprising Treatises on the Principles of Constructujn 
and Design. By G. Huskisson Guillaume, Architect. Numerous 
Illustrations. One vol. i2mo. ...... g2.iM 

WILL.— Tables of Qualitative Chemical Analysis. 

With an Introductory Chapter on the Course of Analysis. By Pre 
lessor Heinrich Will, of Giessen, Germany. Third American^ 
from the eleventh German edition. Edited by Charles F, Himes. 
Ph. D., Professor of Natural Science, Dickinson College, Carlisle, Pa 
8vo. . . • •. . ^1.50 

WILLIAMS.— On Heat and Steam: 

Embracing New Views of Vaporization, Condensation, and Explo- 
sion. By Charles Wye Williams, A. I. C. E. Illustrated 8vo. 

^350 

WILSON. — A Treatise on Steam Boilers : 

Their Stiength, Construction, and Economical Working. By Robert 
Wilson. Illustrated i2mo ^2.50 

WILSON. — First Principles of Political Economy: 

With Reference to Statesmanship and the Progress of Civilization. 
By Professor W. I). Wilson, of the Cornell University. A new and 
revised edition. I2niu. ....... ^1.50 



30 HENRY CAREY BAIRD & CO.'S CATALOGUE. 

WOHLER. — A Hand-Bookof Mineral Analysis: 

By F. WoHLER, Professor of Chemistry in the University of Gottin- 
gen. Edited by Henry B. Nason, Professor of Chemistry in the 
Renssalaer Polytechnic Institute, Troy, New York. Illustrated. 
i2mo. .......... $3-00 

WORSSAM.— On Mechanical Saws: 

From the Transactions of the Society of Engineers, 1869. By S. W. 
WoRSSAM, Jr. Illustrated by eighteen large plates. 8vo. $2.50 



RECENT ADDITIONS. 

ANDERSON.— The Prospector's Hand-Book: 

A Guide for the Prospector and Traveler in Search of Metal Bearing 
or other Valuable Minerals. By J. W. Anderson. 52 Illustrations. 
i2mo $1.50 

BEAUMONT.— Woollen and Worsted Cloth Manufacture: 

Being a Practical Treatise for the use of all persons employed in the 
manipulation of Textile Fabrics. By Robert Beaumont, M. S. A. 
With over 200 illustrations, including Sketches of Machinery, 
Designs, Cloths, etc. 391 pp. i2mo $2.50 

BRANNT.— The Metallic Alloys : 

A Practical Guide for the Manufacture of all kinds of Alloys, Amal- 
gams and Solders used by Metal Workers, especially by Bell Founders, 
Bronze Workers, Tinsmiths, Gold and Silver Workers, Dentists, etc., 
etc., as well as their Chemical and Physical Properties. Edited 
chiefly from the German of A. Krupp and Andreas Wildberger, with 
additions by Wm. T. Brannt. lllusirated. i2mo. ^2.50 

CROSS. — The Cotton Yarn Spinner: 

Showing how the Preparation should be arranged for Differen 
Counts of Yarns by a System more uniform than has hitherto been 
practiced ; by having a Standard Schedule from which we make all 
our Changes. By Richard Cross. 122 pp. i2mo. . 75 

GRANT.— A Hand-Book on the Teeth of Gears : 

Their Curves, Properties, and Practical Construction. By George 
B. Grant, Illustrated. Second Edition, enlarged. 8vo. $1.00 

MAKINS.— A Manual of Metallurgy: 

By George Hogarth Makins, M. R. C. S., S. C. S. Illustrated 
by 100 engravings. Second edition rewritten and much enlari^ed. 
8vo., 592 pages $3.00 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



POSSELT. — Technology of Textile Design : 

Being a Practical Treatise on the Construction and Application of 
Weaves for all Textile Fabrics, with minute reference to the Ir.test 
Inventions for Weaving. Containing also an Appendix, showing the 
Analysis and giving the Calculations necessary for the Manufacture 
of the various Textile Fabrics. By E. A. Posselt, Head Master 
Textile Department, Pennsylvania Museum and School of Industrial 
Art, Philadelphia, with over looo illustrations. 292 pages. 

4to. I5.00 

POSSELT. — The Jacquard Machine Analysed and Explained : 
With an Appendix on the Preparation of Jacquard Cards, and 
Practical Hmts to Learners of Jacquard Designing. By E. A. 
Posselt. With 230 illustrations and numerous diagrams. 127 pp. 
4to ^3.00 

ROPER. — Instructions and Suggestions for Engineers and 
Firemen : 
By Stephen Roper, Engineer $2.00 

ROPER.—The Steam Boiler: Its Care and Management: 

By Stephen Roper, Engineer. i2mo., tuck, gilt edges . $2.00 

ROPER. — The Young Engineer's Own Book : 

Containing an Explanation of the Principle and Theories on which 
the Steam Engine as a Prime Mover is Based. By Stephen Roper, 
Engineer. 160 illustrations, 363 pages. i8mo., tuck . ^3.00 

ROSE. — Modern Steam-Engines : 

An Elementary Treatise upon the Steam-Engine, written in Plain 
language ; for Use in the Workshop as well as in the Drawing Office. 
Giving Full Fxplanations of the Construction of Modern Steam- 
Engines: Including Diagrams showing their Actual operation. To- 
gether with Complete but Simple Explanations of the operations of 
Various Kinds of Valves, Valve Motions, and Link Motions, etc., 
thereby Enabling the Ordinary Engineer to Clearly Understand the 
Principles Involved in their Construction and Use, and to Plot oat 
their Movements upon the Drawing Board. By Joshua Rose, M. E. 
Illustrated by 422 engravings. 410, 320 pages , . 3^-00 

P-OSE.— Steam Boilers : 

A Practical Treatise on Boiler Construction and Examination, for the 
Use of Practical Boiler Makers, Boiler Users, and Inspectors ; and 
embracing 'n plain figures all the calculations necessary in Designing 
or Classifymg Steam Boilers. By Joshua Rose, M. E. Illustrated 
by 73 engravings, 250 pages. 8vo ^2.50 

SULZ.— A Treatise on Beverages : 

Or the Complete Practical Bottler. Full instructions for Laboratory 
Work, with Original Practical Recipes for all kinds of Carbonated 
Drinks, Mineral Waters, Flavorings, Extracts, Syrups, etc. By 
Chas. Herman Sulz, Technical Chemist and Practical Bottler. 
Illustrated by 428 Engravings. 818 pp. 8vo. . . $10.00 



4- 



32 HENRY CAREY BATRD & CO.'S CATALOGUE. 

Davis. — A Practical Treatise- dk the Manufacture of Bricks, 
Tiles, Terra-Cotta, etc. : ^;' 

Including Hand-Made, Dry^'^ti}', Tempered Clay, Soft-Mud, 
and Stiff-Clay Bricks, also Front, Hand-Pressed, Steam- 
Pressed, Re-Pressed, Ornamentally Shaped and Enamelled 
Bricks, Prain Tiles, Straight and Curved Sewer and Water- 
Pipes, Fire-Clays, Fire-Bricks, Gla^ Pots, Terra-Cotta, Roof- 
ing Tiles, Flooring Tiles, Art TiJ^is; Mosaic Plates, and Imita- 
tion of Intarsia or Inlai^ Surfaces, compirising every Important 
Product of Clay Employed in Architecture, Engineering, the 
Blast Furnace, for Retorts,, etc., with a History and the Actual 
Processes in Handling, Disintegrating, Tempering and "Mould- 
ing the Clay into the Shape, Drying Naturally and Artificially, 
Setting, Burning with Coal, Natural Gas and Crude Oil Fuels, 
Enamelling in Polychromic Colors, Composition and Applica- 
tion of Glazes, etc., including Full Detailed Descriptions of 
the Most Modern Machines, Tools, Kilns and Kiln Roofs used. 
By Charles Thomas Davis. Second Edition. Thoroughly 
Revised. Illustrated by 217 Engravings. 501 pp. 8vo. $5 00 

CONTENTS.— Chapter I. The History of Bricks. II. General Re- 
mnrks Co'K-erning Bricks, their Size, Strength and Other Qualities, Orna- 
mental Bricks, Architectural Terra-Cotta, Blue Bricks, Saltpetre Exu- 
dations upon Brick-Work. III. Enamelling, (Jlazing and Ornamenting 
Bricks and Tiles, Earthenware, etd." IV. Selecting Clays for Various 
Kinds of Bricks — The Different Varieties of Clay — The Characteristics, 
Qualities and Localities — How to Color Bricks Red — Kaolin — Terra- 
Cotta Clays — Fire Clays — Exploring, Digging and Marketing Fire Clays 
— Washing Clays. V. Making and Burning a Kiln of Hand-Made Bricks. 
VI. Manufacture of Dry Clay Bricks. VII. The Manufacture of Tem- 
pered-Clay Bricks, Including a Description of the most Modern Machitiery 
Employed. VIII. Kilns. [X. The Manufacture of Pressed and Orna- 
mental Bricks. X. The Manufacture of Fire-Bricks. XI. The Manufac- 
ture of Drain Tiles. XII. The Manufacture of Sower-Pipes. Xlfl. The 
Manufacture of Roofing Tiles. XIV. The Manufacture of Architectural 
Terra-Cotta. XV. Ornamental Tiles, etc. Index. 



V::^ 









